Sorry to burst your bubbles, casuals, but you can rate peoples performance on a individual level easily.
DPS:
Amount of damage, Amount of KB's, KB's on flag carriers/in objective area.
Heals:
Amount of heals, amount on heals in objective area, amount of heals on flag carrier.
Tanks:
Amount of time in objective area, amount of times picked up/carried flag/capped
I'm personally sick of doing 250k damage, have 0 deaths, 10kbs and whats the result if my team is awful? Like 40 warzone commendations, to the THOUSAND I need.