As someone who's joined ~4 social media sites within a kinda small window of time, I really think people tend to have negative opinions about all of them.
DeviantArt is full of fetish-obsessed creeps, Tumblr's the home of immature fandom-crazed gremlins, Twitter's a cesspool of vicious idiots who have nothing better to do than fight with other idiots on the internet, Facebook is only still relevant to racists and other toxic old people...etc.
I belong to all these sites, and these are all things I've heard about them from outsiders. But, interestingly enough, that hasn't been my experience with any of them. =/ So yeah, I've learned to take any hearsay with a grain of salt.
Of course, I don't mean to say that those impressions are baseless...I've gotten a few glimpses of the dark side of all those sites, as one does. But just as you're likely to find trouble if you go looking for it, I think you're likely to have a nice time if that's what you're there for.
TL;DR: Yeah, people have low opinions of DA, but people have low opinions of a lot of sites. It's honestly no worse than any other platform.