I haven't really seen the hate on the Dalish, though that may be because I haven't journeyed to "that part" of the forums. (I just love hanging around this thread for all the Solas love and interesting theories and speculations that people come up with. Not to mention being able to read some of the juicy smut fics.)
With that said though, as someone who's played a Dalish Warden in DA:O and formed some kind of attachment for them, the revelation that the Dalish elves have gotten their history all wrong did kind of shock me, but at the same time, I thought it made the story more compelling. (Though I know some fans in the Tumblr community see it as Bioware purposely taking a dump on the Dalish in general and claiming they did it because Bioware hates the elves, which I seriously don't believe was Bioware's intent.)
I'm just kind of sad that people are using the newfound lore to justify their hate for the Dalish. I know they're flawed and can be pretty nasty to someone who is not Dalish, but that does not mean that they all deserve to die. That's a bit much. 
I don't think that Bioware hates the Dalish at all, I doubt they would give the elves so much attention if they "hated" them. Nor would Flemeth be so involved with them as well.
I, for one, find that twist that they've gotten "everything wrong" as some wonderful storytelling. I mean, I've always assumed that the Dalish must have gotten something wrong in their beliefs after losing so much of it -- or, in another theory, purposely changing things to be seen as more positive (i,e, the vallaslin) -- because there is always a question as to why they do things they way they do, or why exactly they believe in certain things when their Keepers can't provide them with all the answers.
I think the Dalish have the most focused attention of the Bioware story -- they have their own language that we see far more of than any of the other languages in Thedas.
As an aside: there's a reason I rarely leave this thread. I've peeked about, seen the hate, and came right back for everyone who posts here. 