Reddit got popular enough to get out of control and then it'll go down just like Digg did. I've stopped using it because of the Zoe Quinn mass ban a few weeks ago and I only go back for 2 or 3 smaller subreddits with unique content.
Anyway its quality is going down really quickly, it's part of the reason why people are leaving now, it happens to every website that gets too popular. If it's not enforced hard enough people don't know what they're doing but they try to become part of the community anyway without learning it so they just start posting stuff that's really bad and they overuse the site's memes just like Facebook does with rage faces. This ruins every joke created on the website and it just doesn't have a personality anymore.