The reason being that's what a platform like Geocities enables; garbage. It empowers people who are willing to put in basically no effort to make a static page with no scripting. That's not a recipe for amazing content, that's a recipe for bottom barrel content.
Really, any platform that enables everybody to contribute anything they want is going to sink to the lowest common denominator. The platform needs a built in way to highlight the best of it to have any worth whatsoever. Most Twitter feeds are unreadable garbage, the reason the platform is a success though is that it has built in ways to find, discover and follow the very best it has to offer.
It's also got a very narrow use case that happens to coincide very well with the skills of comedians and comedy writers. Geocities' narrow use case only coincides with the skills and talents of artists, and they already have Deviantart and their own gallery websites. There's no compelling reason for them to use Geocities/Neocities as their platform.
Best of luck but I'm skeptical this is going to ultimately be worthwhile.