(ATA: I was an admin on WoWWiki, one of their largest wiki, when it was sold to Wikia. I kept in touch with Wikia employees since.)
They still get the odd email from a delusional Wikia staffer trying to get one of their sites to become a Wikia site, but they immediately turn them down.
It was once a pretty good wiki farm, and I can't complain about the support. Then the skinpocalypse happened.
New wikis are practically the hello-world project for every programming environment that can build a web app, so it's hard for me to understand what's so important about being hosted in Wikipedia, other than to ride on its SEO coat tails.
Why shouldn't Wikipedia be the place for all factual, verifiable, minimally notable information in the world, so long as it's properly organized?
Wikipedia is a long long way from that goal, even if we exclude fictional-universe nonsense. Pick nearly any historical subject; dozens of books filled with information translate to a few sparse Wikipedia articles. That's terrible.
For instance: someone downthread complained that WP was missing coverage of local bands and an interesting BBC documentary. The BBC documentary should be in Wikipedia, and if it isn't, it's probably because whoever wrote the stub article for it wrote it poorly; someone else should re-add it. But the local bands most likely fail both notability and verifiability: if nobody has written about them, (a) chances are they aren't notable, and (b) whatever is notable about them can't be tied to a specific reliable source, which would make a Wikipedia article about the band original research.
A really common place you run into trouble with Wikipedia is when your proposed article breaks new facts about its subject. That's not supposed to happen. Wikipedia is a tertiary source; if it makes a claim, that claim needs to be sourced from something else. "Original research" is a confusing term for this, but it makes a lot of sense once you grok it. From the perspective of an encyclopedia, there isn't much difference between someone's random harebrained theory about cold fusion and a discussion of the lineup of some New York hardcore band nobody's ever heard of outside of NYC.
I think fans contribute to Wikia more out of convenience and inertia.