My band shared the stage with a guy who had to plug a laptop running Ableton into the board and sing over his studio tracks because his backing band bailed on him. It was basically karaoke of his own music, but he still put a s..t-ton of energy into his set and managed to give us a good show. Most people aren't gonna care, as long as you have charisma, good material, and they know you're doing SOMETHING on stage. If anything, they may just come away from the experience saying "Well, hey, that was interesting!" As for bands who have backing tracks... Nobody complains about that but snobby musicians and armchair "keepers of the laws of Rock n' Roll"... best advice I ever got: you really shouldn't care what those people think. In fact, after a while, you may start to realise how fun it is to piss those people off.