As the game changes, we want to complain that a hero that once countered someone, no longer does. Bastion still has plenty of counters, and the Tracer nerf invites better team play to deal with a Bastion rather than the standard - farm pulse bomb - kill, that’s it.
Which - IMO hasn’t been affected as much as you think. Let’s do some basic maths.
Bastion is stationary target and pretty big.
Tracer does 3-12 dmg per ‘shot’ (one shot from both guns)
She has 40 ammo per gun so let’s assume you get 0 headshots and get the minimum 3 damage.
3 x 40 = 120
Pulsebomb = 300
You should be able to easily pulse bomb a bastion, empty a clip and recall
Junkrat still makes Bastion an easy kill, other decent heroes against this comp are DVA, Sombra, and with good positioning Zen / Widow / Ana
Why you may not be able to as easily take out the Bastion now, Tracer is still just as good as ever at taking out other easy heroes.