I'm not entirely sure that most don't object so much to loading them as to sorting them, although some people really hate changing their press over.
It's another step for the reloader, came about for no palpable reason, and TMK everyone that makes/loads small primer still makes/loads large primer in 45, things were simpler when there was a standard.
Changing my press from one to the other is easy enough, so I keep both, with no preference, but if I know I'll be leaving my brass lay I'll probably take smalls.