Logic behind "no dunking in warmups"

[KingTripleJump]

Anyone?

I hated the fact that when I was in high school, the refs wouldn't let us dunk and now that I officiate, I have to constantly remind players not to do so. So what's the logic behind not dunking?

I always assumed it was to prevent the players from screwing up the rims/backboards before the game even started. You can't exactly get "hurt" dunking in pre-game. Well, some people can...