What do you think about people singing/covering songs they can't relate too?

When I was in music school I had to sing songs I didn't like all of the time. It can be done, but lacks heart. One needs to try to imagine themselves in the position of the composer (or speaker in the song) and work from there. the average musician who writes their own songs wouldn't compose one they couldn't relate to or it would be wasting their time. With the examples you gave, it's kinda like looking at the full house crew. Drug addicts, numerous marriages and arrest records- then look at the show... go figure.