ok, quick explanation:
if you collide with someone, it means that you've collided with them on your screen, ie, your PC has registered that you've gone and rammed someone, or they have rammed you.
now, if you collide, and they dont, it means that on the other guy's PC, you flew close to each other, but he didnt register any contact, this is due to inevitable internet lag, (you can only go as fast as the speed of light

)
imagine what would happen if both players took damage from a collision?
imagine you're duelling with someone with a bad connection, and on his PC, he registers a contact. now on your screen, you may well be 100 yards apart, but my your new rules of 'everyone takes damage in a collision' you would collide too!
it wouldn't be fair if you died for no reason other than the other idiot ramming into you on his PC would it? it is the way it is a for a reason, and that reason is fairness
