What happens is that people who happen to be there will get up and dance because it's familiar, and that's good enough for a crowd that just wants to party. That's typically a crowd there for the event, not for the band.i agree with you. the same tired old covers are usually played because of a lack of talent or creativity in a band. People out there like the songs so much it doesn't even matter if you butcher them.
I find a cover band who pulls out a well known song that you DON'T hear every other covr band playing to be far more interesting and worthy of respect than hearing "Mustang Sally" for the 158,000th time...
But it's nothing special, and that is what a lot of bands don't understand. Nobody's going out of their way to come back to see the "nothing special" band a second time at a different event, but they are going to go out of their way for something that is equally fun but also is something special. Yet I hear the tired arguments over and over that those 40 songs are the only ones to ever bring dancers to the floor. Yeah, no.