In that case proxy votes completely eliminate the advantage of in-the-flesh meetings. As things are, no one needs to attend in order to vote.
In fact, although science wiki has an official member list (which I had to add myself and Josh to, it being quite out of date) I dont think you have to be on this list or to ever have participated in any science event to vote for science chair.
I definitely see the need for some screening on the basis of committment, but dont really see just showing up this sunday or emailing a proxy really accomplishes this. Not sure what would. If it was based solely on teaching classes, I’d have no vote, even though I do in fact do plenty of work for the committee.