Yes, I find it dumb to pay more than one deposit down if you got in every school you applied for and are deciding one or the other. mostly, such a move is dumb because you're wasting money, but it also prevents and delays the adcom from getting to its waitlist where someone on it really wants to go to that school.
If you put more than one deposit down, it isn't because you put a G down at two places at the same time. It's because you got into school A and school B, but you got into school A but WL'ed at school B. You eventually get into school B and accept that school's offer, but you lose the $ on school A. That's fine and that happens a lot. But otherwise, I would commit only to one school.