It makes no sense to replace a bolt or pin that isn't needed.
Agreed. Except, apparently, when it's convenient for the local guides. I'm thinking of the piton at the start of the Roseland traverse.
There is a story behind that piton, and it has nothing to do with guides or the guiding services. Someone asked a local climber to put it there; I believe it was in 1978 or so.
I'm talking about the replacement a few years ago, not the original. There was debate on this forum and rockclimbing.com about whether it was needed. Someone said one of the local guides had eventually replaced it after it had fallen out/pulled/was removed/whatever.
I love that pin, too, by the way.