Having unlimited ability to vote won't keep over-zealous followers from just voting for everything. At least now they have to make some decisions about what they wish to tout as the formative questions to represent their proposal.
You can't really control how and why users wish to vote, but if folks want to play this game of shuffle-the-vote assembly line, they do so at their own peril. The Community Team evaluates every proposal about half way through the Commitment process, and pushing a half-baked proposal through makes it that much likely it will be rejected in the final evaluation. And there's nothing saying that a poorly-supported launch is going to make it out of private beta.
So there's much more to this than a simple numbers game.
There is a growing contingent of users who realize that if you are only voting to push the proposal through regardless of substance, you are only hurting your prospects of launching a successful site. Take a look at my answer in this discussion about
Prevent up-votes for questions at 10 or more
It is my belief that the efforts to shuffle votes "efficiently" over any other consideration is what doomed the competitive programming proposal by pushing it through before it could be demonstrated that it could be a useful site.
So we're not looking to compound the problem of users pushing proposals through by voting indiscriminately. Allowing unlimited voting will only hasten the problem of launching a site with insufficient momentum and support to actually sustain a healthy community.