The simple fact is that the margin width makes little difference. What we are talking about here, in effect, is a 50px vertical difference. People can currently have signatures that are double that vertical space, at 120px high. So for a slight increase in vertical space (and that only for users that choose to use the increase), you get double the pixels available.
If you don't like seeing other people's avatars, turn them off. If you don't want to add to the vertical increase, make your own avatar smaller.
All this arguing over how votes should be counted is childish.