If R.E.M. had broken up after New Adventures in Hi Fi I think they would probably be a lot more respected these days. I mean, I like a lot of Up but R.E.M. were a band where every member played an integral part in the creation of their music, and losing their drummer could and probably should have been a sign that they should call it a day. In fact, in many ways the direness of Around The Sun can be considered Bill Berry's fault, since apparently he was only going to leave the band on the condition that they continued to make music without him...
Actually, imagine if The Beatles had continued into the Seventies without, say George. How different would their reputation be today?
Better to burn out than fade away etcetera etcetera.