they nerfed the counters to dive and reinhardt shatter and hog out of the game so people have to work with whats left. With no hogs around genji dva winston tracer all have much less to fear. Also harder for ana to defend against flankers with the damage nerf (use to 2 shot tracer), with so much damage in quick bursts and no position being really safe playing mccree is basically suicide and even if you manage to be useful dva will just fly at you and block ur shots then you die to the incoming dive. He use to stick behind reinhardt but thats gone so people stick to soldier/tracer or genji/tracer always... mccree who is suppose to counter her doesn't really if she is good she can disjoint the flashbang with her blink but soldier who can throw down his heal and shoot her a couple times then helix rocket. It comes down to the heroes in use and what works against them.. which is the same heroes because theres only one meta right now since blizz insists on leaving half the heroes in the game non-viable status.