It’s not a stupid question. One of the problems of the Dead Ladies Club is that it works in extremes; these women are either heavily romanticized or heavily vilified with romanticization being the most prominent reaction. We don’t know them. We don’t have a sense of their personality or beliefs or living experience to define who they are. Our knowledge of them comes from secondhand accounts that often did not know the characters all that well and are colored by character bias. And that’s how the dead ladies become idealized concepts with their textual importance defined by their absence and their personhood defined by their desirability and beauty, frozen in time on their pedestals.

However, you assessment of how Elia is regarded is not accurate and it’s
that that contradicts the idea that Elia is romanticized. While we do
have Barristan’s description of Elia as a good and gracious with a
gentle heart and sweet wit which might be somewhat idealized, that description does not stand on its own.
Besides two lines from Barristan, almost everyone (outside of the Martells) who thinks of Elia does it in a condemning tone, whether implicitly or explicitly. It might be argued that these characters’ denunciation isn’t centered on Elia’s personality, whereas Barristan’s praise is, but honestly, even Barristan’s words does not build a personality.
Courtesy and wit are things that noble ladies,
especially born princesses, are expected to display in their daily
lives, much less in any ceremony. That does little and less in telling
us who Elia was as a person. She was good, but what does it mean that she was good?

But again, even that bit of positive recollection is undercut with how Elia is viewed by the rest of the characters. Most people actually only think about Elia in the context of her murder, but those who do think about her life pile up on her. She is seen as lacking, as unworthy of Rhaegar, as the reason Rhaegar needed Lyanna in the first place. I wouldn’t discount knocks on her appearance as shallow and irrelevant to how she is remembered, partly because that is a clear indication of the racism and ableism that is driving negative reflections of Elia, and partly because it’s exactly that that’s been used to argue Elia’s unworthiness and blame her for Rhaegar’s actions. I’ve argued before that common racism and ableism makes it far easier to scapegoat Elia and blame her for what Rhaegar has done than to hold Rhaegar accountable for his own actions. God forbid someone blames the sad handsome white boy for his own blunders, no it’s his brown wife that is surely to blame. And lo and behold, that’s exactly what happens. In the same scene where Barristan speaks of Elia’s graciousness, the dialogue is about how she supposedly drove Rhaegar to his folly.

“Princess Elia was there, his wife, and yet my brother gave the
crown to the Stark girl, and later stole her away from her betrothed.
How could he do that? Did the Dornish woman treat him so ill?”

“It is not for such as me to say what might have been in your brother’s heart, Your Grace. The Princess Elia was a good and gracious lady, though her health was ever delicate.”

Dany pulled the lion pelt tighter about her shoulders. “Viserys said
once that it was my fault, for being born too late.” She had denied it
hotly, she remembered, going so far as to tell Viserys that it was his
fault for not being born a girl. He beat her cruelly for that insolence.
“If I had been born more timely, he said, Rhaegar would have married me
instead of Elia, and it would all have come out different. If Rhaegar
had been happy in his wife, he would not have needed the Stark girl.“ 

 

Dany automatically assumes that it was something that Elia had done that caused Rhaegar to humiliate her and abscond with Lyanna. Viserys concludes that Rhaegar’s actions were because he wasn’t happy in his wife, again assuming the fault lies with her. Barristan needlessly brings up Elia’s health unprompted emphasizing that she was “flawed” and almost giving a substitute motivation for Rhaegar – the problem isn’t in how Elia behaved, it’s in how Elia was. Barristan also doesn’t quite disagree with the idea that things would have been different if Rhaegar had married someone else. In another part, he gracelessly refers to Elia as a “kitchen drab” while comparing her unfavorably to Ashara Dayne.

In a situation where she was a blameless victim, Elia still gets the blame, even from the guy who spoke for
her
positive qualities, while Rhaegar gets the sympathetic treatment. (Dany later describes his death as him dying for the woman he loves, and exactly no one ever thinks of how he sacrificed his innocent wife for that so-called love.)

Kevan Lannister displays the same belief of putting Rhaegar’s actions (and the rebellion by association) on Elia. If only Rhaegar had married Cersei….

 If Aerys had agreed to marry [Cersei] to Rhaegar, how many deaths might have
been avoided? Cersei could have given the prince the sons he wanted,
lions with purple eyes and silver manes … and with such a wife, Rhaegar
might never have looked twice at Lyanna Stark. 

Note the words Kevan use. The sons, purple eyes and silver manes. If that’s not a knock on the Dornish-looking Rhaenys, I don’t know what is. Also, that subtle dig at Elia.

Jon Connington is on another level of awfulness.

Jon Connington remembered Prince Rhaegar’s wedding all too well. Elia
was never worthy of him. She was frail and sickly from the first, and
childbirth only left her weaker. After the birth of Princess Rhaenys,
her mother had been bedridden for half a year, and Prince Aegon’s birth
had almost been the death of her. She would bear no more children, the
maesters told Prince Rhaegar afterward.  

The man is talking about how Elia almost died to give Rhaegar an heir, but his take somehow is still that Elia was unworthy of Rhaegar. She gave Rhaegar two children but Connington’s feathers are ruffled because she couldn’t have more. Please remember that he still has the audacity to turn to Elia’s kinsmen to help him in a war that he is waging to make himself feel better.

(Screw you, Jon)

Then there is Cersei, the Light of the West herself.

It had to have been the madness that led Aerys to refuse Lord Tywin’s
daughter and take his son instead, whilst marrying his own son to a
feeble Dornish princess with black eyes and a flat chest.

The thing is that comments about physical appearance aren’t just about physical appearance. They are about Elia’s race that inherently branded her inadequate in their eyes (oh those black eyes that she passed on to her daughter). They are about Elia’s health that must have affected how she looked (she was not long out of her sickbed from Rhaenys’ birth at Harrenhal, and she was likely already pregnant with Aegon at the time). They are about her perceived inability to provide Rhaegar with something he needed: more heirs, a beautiful wife (she was not enough to hold his interest, not “a rising sun” like Cersei), happiness (how did she treat him? Did she “mend his hurt”?), etc. Even the words used to describe Elia’s beauty is the same that’s been used to describe her health implying fragility, weakness and inferiority. It comes down to the same implication: Elia is deficient. Which makes her a convenient scapegoat for every douchebag with an agenda, like Yandel.

It is not known who murdered Princess Rhaenys in her bed, or smashed the infant Prince Aegon’s head against a wall.

Some whisper it was done at Aerys’s own command when he learned that
Lord Lannister had taken up Robert’s cause, while others suggest that Elia did it herself for fear of what would happen to her children in the hands of her dead husband’s enemies.

Yeah, he just perpetuated rumors that she killed her own children. Can’t bring up Tywin’s name. Nope. So let Elia take the fall for another white guy.

So Elia’s reputation really comes down to two positive lines about her cleverness and grace, and an onslaught of people implying she is to blame for the rebellion and the deaths that followed. Even the warmth in Oberyn and Doran’s narrative is too little to counter that, especially with how it is overshadowed by the justice and revenge narrative of the Dornish plot, and how neither Oberyn or Doran are PoV characters. And the ones who are PoV just don’t remember Elia, so we only get bits and pieces. I don’t think that sells a romanticized narrative of Elia at all. Compare that to how someone like Rhaegar is talked about, or Arthur Dayne, or even other Dead Ladies like Lyanna, Joanna or Ashara, and you’ll see the difference.