Mohamed Magdy wrote (in part):
Other ideas say that Wikisource project is special somehow that some of the languages will never be big enough (text collections, contributors etc...) to deserve its own domain or there will never be enough community for it..and because of that they are better placed in one place (I don't really see the objection of making new sub-domains or wikis, does it cost?)
I am not at all active on Wikisource, and I have no opinion on the topic in general. However, I'll say just one thing:
The advantage of having smaller communities on one wiki is that there is then one central watch list and recent changes list. This lets people monitor vandalism, in many cases even for languages they don't speak. With a very small community, vandalism can run rampant without anyone noticing it for long periods of time.
-Rich