Well anyways... For music and cover tracks (tracks that are made, not from the orinigal artist but other most usually worst bands), there is a good reason for that. And mainly that amatuer music productions are simply...bad... comparing to the multi million dollar industry tracks. And so any attempt to redo for example 'Creep' by Radiohead, would probably be a negative advertisment for the original.
It's not that hard to understand.
I have to copyrights and I don't want you to do anything about it. Period! It does make sense really.