I hear ya. I could see their point of view I guess since a majority of what is on DA is, well, art. But a you say, there's a prose fiction option, so it's all good, I say. Besides, if they don't like it, it's not like anyone is putting a gun to their head and forcing them to read it, haha.
I'm glad to hear you're interested in the forum! Mostly we discuss different aspects of fantasy and sci-fi writin. We also do roleplays, and help each other out (through motivation) in writing longer projects and even novels, and we also do something called writing duels, where we compete against each other in writing short stories in various subjects. It's pretty fun.
All in all, that's what we do, but the main thing we're about is just having fun and being good friends.