a few bullets to kill some one doesnt punish team work it encourages it, with volume of fire and lanes of fire, once again with supression fire to deny acess of an area
you seem to be unclear on the game being played
it's is not a series of hallway defence rooms, objectives in brink are about planting bombs...then defending said planted bomb so enemy teams dont disarm it. escorting, interogation, capping command posts, collecting intel, opening paths for faster travel.....and parkour. suppresive fire wont happen too often when the lights and mediums can hop over some shipping containers and get past you while your focused on a door.
more bullets to kill is to assist in objective completions. if you can kill the bomb planter too easily they'll never plant the bomb, if it were a deathmatch style game then maybe less bullets would be better. but as long as objectives need completing it's open to stalemates way too often if people can snipe or suppress hallways.