Reddit's management simply has an economic incentive to promote these gems to defaults to draw in users and make the site more attractive to those unwilling to dig down, but in the end this hurts those subreddits. I suspect this will be reddit's downfall. It curates some grass-roots communities that are self-managed, watches them grow, and then throws them to the wolves of Joe and Jane CasualAsshole. Now these gems have been thoroughly bro-ified, meme-ified, and politically-correctified with endless arguments web commentators like to get into (religion, politics, accusation of various 'isms', etc).
So yeah, I eat my own dogfood. I know writingprompts will never be good again the same way I know 2X suffers from the same thing with casual visitors. The difference is I know its a symptom of reddit default changes and don't think there's anything here regarding "education" that can fix this. Reddit's need for growth and popularity means decent subs become shitty subs over time. Heck, even when they remove defaults, the damage is done. /r/atheism will never be this philosophical-type sub, it'll always be meme-ish anti-Christian crap. Whatever mindshare they hoped to attract long left, the same way the writers I used to recognize on writingprompts are long gone now.
In other words I blame reddit management, but she blames reddit users. I think those are pretty different takes on the source of those problems. She seems to believe some heavy-handed "reddit 101" is going to fix everything. I believe that is hopeless once you reach the level of a default sub. Shitty users are always there, its how you manage them, compartmentalize them, incentivize them, etc that matters.
Management's economic incentive is purely to get more money from existing sponsors and to get more sponsors - and if they had to close down /r/writingprompts to achieve those ends, it'd happen. Look at how Reddit handled the celebrity nudes leaks were handled.
I think it's a good tradeoff to let these users run free on lax subreddits and moderate heavily on others, provided the moderating tools get better and make it easier on the mods.
But it's not asking too much of that same cat-and-meme based system to be a focusing point for decently written short-stories and a good place to discuss books?
I mean, you're saying that it's asking too much of people that they just click 'unsubscribe' on twox - and that having the barest understanding of how subreddits work is just too much.
And that's the community you're complaining about your seeming inability to farm quality prose from? I'm as tired of stories ending in the "tree-fiddy" in-joke as you are, but maybe there needs to be a higher barrier to entry than 'spends time on reddit' for voting, and while 'is able to read a couple dozen default sub rules' isn't that much higher, it might encourage people to at least read the rules before spouting off.