The mistake they made was allowing visitors to trigger the generation of articles via visiting any arbitrary URL.
A more resilient concept would have been, have a few "seed" articles in place, and then only allow for the creation of new articles by clicking a link in an existing article.
I vaguely remember a game someone made up (probably on 4chan) where the goal was to click "random article" and see how many clicks it takes to get to Hitler's page. I remember it being fun AND informative.
As the co-author of the project: the whole reason was to allow everybody to hallucinate what they want. If it was their will to research such things on there, then it shall be. But yes, it is kinda sad.
Just in the comments, right? That is where I see it. If I were the site owner I would just turn comments off. It was a cute idea when someone on HN suggested it, but without moderation open commenting becomes a cesspool in a hurry.