Most of the people playing this game have no idea how to play.
Most players dont do basic stuff they don't spot, don't revive, dont' drop ammo or medkits, don't tracer armour or RPG/CG it once it is tracered, tank drivers drive off while you are repairing, engineers dont' get out to repair if you're the driver, drivers only decide to move away from a mortar strike once they have been hot 3 times and the tank is on 9 health.
BF3 could be the best game in the world but playing it with numpties will always make you rage quit.