If a thermal can see through or behind a bush, then the bush is not thick enough to hide the animal from visible eye either. This fits within physics.
And in nearly all hours of legal shooting light, a 1000+ stumps and rocks on the hillside all look like warm bodies. Its NOT a cheat code. This is only revealed once you've actually used one, which again, is 99% of the problem here. Inexperience with the subject.
Besides that, whether you see the animal with a thermal or your eye, you have to make the decision to further pursue the animal, likely stalk up on the animal and/or close the distance, wait for the shot to present itself, and then launch the projectile at it. If simply locating the animal changes the sport from hunting to shooting, then outlaw technology that allows glassing as well, as I've articulated there are multiple steps immediately following in the process. Not even talking about all the steps preceeding (getting yourself in a position and setup to locate) and proceeding the kill (retrieving, packing out, etc.)
Turns out hunting is not a universal definition one person can articulate as their own.