At first it was all about presenting data in an original looking way. In the end it was about pushing political ideas in your throat using a plain bar graph. It was not about sharing something interesting you found but about taking advantage of a captive audience.
I’d say it’s more that it’s hard to stay in the Goldilocks Zone of being popular enough that there’s sufficient content being posted but not getting so popular that new users see the good content and think “I can do that” and just post shit content. Either way you need good mods keeping the shit out!