Yeah, probably "old" wasn't the best choice of words.  I have friends who are using original exhausts that are 20+ years old and in good shape, so I don't really think that 8,000 miles is an average life for an MC exhaust.  It likely depends on packing material quality and how/where it's used/stored.  Not sure if the previous owner stored the bike outside or what, but for some reason the muffler baffles/packing seem to have deteriorated on mine.  Still looks like new on the outside, but sounds like crap.  Gives me an excuse to play around with a different exhaust and see if I like it.