It happens, Mike. Keep in mind folks like us are often pulling bikes out of the trash or thrift stores; we're really the last stop. At least some of the usable parts get recylced; I recently pulled apart an old Ross for the Shimano 600 gruppo, for instance. I've got a Miyata in the basement I bought for the Brooks professional saddle on it; paid ten bucks for the two bikes.

Many of the other parts on these bikes I'll likely use to help keep friends and neighbor's bikes on the road, and some will wind up parted onto other projects. I look at it as a good way to keep bikes going on the cheap. I've lost track of the good parts I've pulled off old bikes where the frame itself was in horrid shape.