People go there to vent because no one in the larger community understands them. SRS is of course a place where they are understood.
It’s like a tumblr making fun of fundamentalist christian screeds. It’s not intended to convince any fundamentalists that they are wrong, but it’s a place to vent and laugh together with like-minded people.
If "no-one understands" a typical SRS'er, why do they have I-don't-even-know-how-many-now subreddits with healthy numbers?
If it exists solely for the purpose of venting (not a downvote brigade, wink wink, don't touch the poop!) and not for accomplishing anything else, then why do SRS'ers so often seem to be charging into other parts of reddit and getting into such dramatic arguments?
Finally, if you really just want a place to make fun of stupid crap? Try /r/worstof or /r/subredditdrama, both of which actually do that.
These two sentences do not go together.