I agree with everything Rick Beato said. He gets it.
Lots of good comments in the thread, so I'll try to avoid saying what's already been said.
I think it's cringeworthy to hear somebody try to pawn off an entire pre-recorded song while miming the vocals and pretending to play the instruments. But I enjoy hearing a talented singer/ musician play and sing along with trax when its clear that he/she is actually adding the same thing to the show that he'd be adding if the rest of the music was being played live. It takes talent to play and sing well no matter WHERE the rest of the music is coming from.
Likewise I think it's hard to listen to a full band when any of the members are terrible. So it isn't the full band that makes it listenable or objectionable, it's the presence or absence of talent... and the more talent there is on stage, the more I'll enjoy it.
As far as the question of "cheating" is concerned: cheating implies that rules were broken. The venue makes the rules. If they don't want backing trax, the people who use them will never get on that stage. The next hurdle is the audience's standards. If the audience hates it, they won't be back, and that means the performer probably won't be back either. The fact that the use of backing trax has become so common tells you that audiences and venues generally accept their use. Beyond that, its just personal preference.