I've been trying to work out what it is that some people lack that leads to their utter failure to understand Solas. I don't know anymore, I thought it was a simple case of empathy, I'm not so sure anymore. *shrugs*
Perhaps it is just a simple lack of interest, which is kind of tragic.
I've been trying to convince my sister to play DAI and to romance Solas (it's going well so far*!), and her main problem with Solas was he seemed, off the bat, pretentious and boring. I basically spoiled the whole thing for her and explained his story up and down, and now she thinks he's interesting.
The thing with Solas is because he does come across as a know-it-all (even the way he introduces himself reminds me of Hermione) he'll immediately turn certain people off. To like Solas you have to want to get to know him, to take him outside with you to listen to the banter. You have to want to take all the investigate options and listen to what he says. And for anyone who's turned off by him from the get-go, that's unlikely to happen. From what I've discussed with my friends who've played it, Solas only became interesting for them after he left the Inquisition (main game epilogue and Trespasser).
Now I'm not saying this is down to the writers making a fuckup. Anyone who listens to Solas' full story will admit he's a damn interesting character despite anything else he is, but he takes a bit of work. For some people.
A while ago I mentioned how I now quite like Josie, despite every playthrough I'd ever done before not really noticing her. That was the same thing for me. I didn't listen to her, I took investigate options but didn't fully explore them, and I took the quick route with her personal quest. But then in my latest playthrough I took my time with her, and found myself really liking and appreciating her, whereas beforehand I found her dull and a bit irritating (that's the accent though).
TL;DR: Different horses for different courses.
*If going well means I play the game for her and she chooses what she wants to say. But she's done a few flirts with Solas so that's something!