I truly don't get it. I personally own a print set of the Encyclopedia Britannica, 11th edition, as well as the current Britannica on CD. But I also must own at least a dozen specialized "encyclopedias" that cover narrow topics of interest to me in depth.
I thought that there was consensus that Wikipedia a) is an encyclopedia, and b) is not "an indiscriminate collection of information." If so, Wikipedia has bounds, set not by disk space, but by a shared vision of what should be in a general-purpose encyclopedia.
What's so bad about dedicated organizations creating Wikipedia-like encyclopedias devoted to in-depth coverage of narrower topics? How is this different from Wikipedia breaking off "sister projects?"
As far as the end-user is concerned, if you want specialized knowledge of webcomics it makes sense to go to Comixpedia. And if you do a Google search on some relatively obscure webcomic that is in Comixpedia but not Wikipedia, it will find it for you just as effectively as if it had been in Wikipedia.
This sounds like a Good Thing to me.
I mean, it's not like "I, my Wikipedia, am a jealous Wiki. Thou shalt have no other Wikis." How do specialized Wiki-based encyclopedias hurt us in any way?