I like the Stephenie Meyer books, and I'm reasonably literate. I don't think it's necessarily an 'either or' decision.
I really enjoy a lot of books that many others would dismiss as crap, so I know how you feel.
I was at least expecting to somewhat enjoy Twilight, even if I thought it was bad or silly. (and yes, I know I just skimmed it) But I was surprised by the writing and couldn't even get any enjoyment out of it.
I have to comment here, as well. It's not like I have high-fallutin' literary tastes, either. I find though, that there has to be something about the story that captures my interest and imagination. Whether I enjoy the story stylistically, plotwise, the way the characters are written or for the overall themes, I can be extremely forgiving about some less than stellar elements as long as I'm enjoying some aspect of it.
To me, in this series, the writing was bad. Bad fan-fic bad. To be fair though, I thought Myers showed a bit of improvement over the course of the four books. The plot seemed to be an afterthought throughout much of the series, where Myers would spend three quarters of the book focusing on Edward and Bella's tru-luv, or their angst about said tru-luv, and then toward the end she would think "Oh shit! I need to stick a story in here!" and then she would go on to insert some contrived nonsense. The ending sequence of the series was one of the most anti-climactic things I've ever read. I was very disappointed with that, even with my already very low expectations. The entire thing reeks of wish fulfillment.
The characters are incredibly one dimensional, and that's a real shame, there could have been great development in a story like this. Bella is 'ordinary,' and yet every male wants her. She's pretty much perfect, other than her one flaw, her endearing clumsiness - WHICH IS MENTIONED EVERY SECOND PARAGRAPH. Ugh. Edward is even more perfect than Bella. He's god-like gorgeous, he's emo and angsty, but hey, these are admirable qualities in this book! So is his tendency to be stalkerish and controlling, but hey, he's only doing it to protect the little lady, so it's okay, it's for her own good!
(Sorry, I'm getting into the parts that really piss me off now, and like Dennis Miller, I feel a rant coming on.)
The themes are what really get me. They've driven feminism back decades.
(Vague spoilers ahead)
High school girls should live for their boyfriends, to the exclusion of just about everything else in their lives! And if their boyfriends are controlling, it's just out of love, really! And if the relationship ends, suicidal gestures are the way to go! Also, it's perfectly fine to bring another guy into the picture and lead him on to assuage your grief and neediness - there's no need to develop your own life and interests! And, if a guy essentially forces himself on you, it's completely acceptable for your father to approve, because he'd rather see you with that guy, than with your bf! No one ever suffers consequences, and everything turns out just fine.
Just. Ugh.
And those few issues are barely scratching the surface.
I did find the last book more readable than the others, though. Maybe by then, I'd invested enough time and energy into it that I was going to see it through to the end, dammit. Oddly, that book was very divisive in the fandom, leading many to consider the series a trilogy by denying the existence of the final book, because it didn't turn out the way that they wanted it to. It just sort of floors me that it wasn't until that point that fans started to have problems with the story.