Why do the Bauer vapor skates have an aggressive stance?

They don't...The stance you're talking about is the Rocker of the skate which all skates are shipped with a neutral rocker...If you get the skate profiled to have a forward (aggressive) or backwards (defensive) lean then you change the rocker or the stance...You should get your skates profiled a couple of times per year...This is different than getting them sharpened which you should do at least after 8 hours of skating on them.