"Not angry, but in many cases I think they would become amused and stop listening"

Totally agree with you Jim. If the singer has no interest in what Scots think then fair enough but I imagine the very fact that someone is trying to sound Scottish means they are attempting to get it sounding as geniune as they can. Don't know why the other poster had to bring an almost racism thing into it? Plain fact is that whether one is acting or singing - a bad accent risks ruining the performance. At least for those who know the accent!