Toby-
Anyone is of course free to start their own project on their own servers, but a Wikimedia brand project should have support from a substantial number of, er, Wikimedians. We're not a wiki hosting provider.
Since when does Wikimedia take votes to make these decisions?
We never did. I proposed that we should start.
A substantial number of Wikimedians /does/ want to do Wikibooks.
Certainly.
I don't need any vote to prove this.
A vote would help to determine if there are many Wikimedians who are against the project. I would have voted against the Wikibook project in its present "Textbook" form, for example. There are many projects where there will be dissent among Wikimedians on whether they should be operated by Wikimedia or not. Take POV projects like Disinfopedia, for example -- I'm sure there are many Wikimedians who like the idea and would love it to run under the Wikimedia banner. But many others would be against this, either because they see NPOV violated, or because they see *their* POV violated.
In that case, it would not be enough to simply say "Look, it's quite obvious that many people want this, so quit yer whining already." A formalized voting process after the project plan has been finalized helps to address such concerns, and makes sure that a large number of Wikimedians is exposed to every new idea -- if not in the planning phase, then in the voting phase -- and gets a fair chance to voice their dissent.
The alternative would be to let Jimbo decide in each individual case.
Regards,
Erik