I don't think this place would turn out any better without moderation and even with it, it would be an extremely hard task. With time, the people within it would turn out to be the same, specially considering that many people would also be, well, the same people, there really aren't "new" dota users out there.
Let me explain. What we see happen on the subreddit is the result of an "hands off" approach. The moderators are, despite it all, not the kind to frequently put a stop to users' ranting. Chains of [removed] and verbal warnings are extremely rare. What we got is just people on their default attitude with one another. So if we want something different out of the same userbase, the question becomes: What rule to enforce to foster a better community? And there's the problem. I don't think anyone in the sub has individually broken any rule. I don't think anyone was individually so much of a little shit gremlin that they primed everyone else. There was no perceptible turning point and no apt place for a moderator to put their feet down.
I do recommend reading less eSports-focused threads. That's where the highest concentration of people collectively being said gremlins is found, except maybe within matchmaking whining threads. But yeah, right now, in the middle of a Major, a Major with several TI-slot decisive matches, I understand that it's hard.