I went to a photographic exhibition a few years ago with 2 metre wide prints. They were awful, un-interesting snapshots of mundane subjects which would have looked bad at 6" x 4" and someone had added a note to that effect in the visitors book.

I like a good quality large print but a bad photograph made bigger is still a bad photograph in the same way that if I played my guitar badly, it would be just as bad through a bigger amplifier!