Btw I don't think the No voters matter at all, if we have 500 people voting and 400 vote No and 100 vote Yes. That would mean 100 people would most likely play the league active, I think that's more than enough to maintain a league with activity, right?
And MI, can't you enforce people to vote that visit your site when they log-in? You would get better results, I know some sites that, when you login, basically force you to vote. It really doesn't take a lot of time for someone to read 1 sentence and then decide yes/no. I think you should work on such feature for important votes like this.