I strongly believe causality runs the other way... becoming a default reddit puts you into an Eternal September that no community could possibly survive.

But in the end, the result is the same.

AskScience is a default sub, I think, and they've survived alright. Interestingly, AskHistorians asked to not be a default sub-reddit for precisely the reasons you've given.

They have something like 500 moderators though so there is that.

They used to ruthlessly remove everything without an academic source, however interesting - these days I feel more and more fluff is getting through.

I think you are very correct.

Maybe one of the nice things about UseNet was that you could only be signed up for a forum that you explicitly looked for? That at least forces the trolls to go out of their way to interfere with general-interest sections, not just go after them out of laziness.

What's wrong with Reddit is the "default subreddit" concept and the difficulty of subreddit discovery. Building in some form of interest based subreddit discovery would go a long way to de-emphasising defaults and (eventually) mitigate much of the vitriol.

There is also something to be said for educating users on the effects of anonymity.