Pharah, Junkrat, Reaper, Tracer and even fucking S76 can kill a turret with minimal risk. Hell even I can kill a torb turret AS TORB with minimal risk. There is a slight delay between acquisition and when it starts firing and its range isn't that long at all.
For that reason good Torbs will put their turrets where it forces people to COMMIT to taking it out (behind corners with narrow sightlines) but where it still has enough coverage to make a difference. But even then once the other team is irritated enough to commit to taking it out, there isn't much a torb can do on those maps where there ISN'T a lot of good turret spots (Ilios: Ruins and Lijiang: Night Market).
Recently I've been seeing more and more teams that will drop everything they're doing just to fucking shit on my turret, and it makes me want to pitch my monitor at a box full of puppies.