It IS rude to do it, but it is also TRAINED in most modern pistol classes (and I mean real defensive classes, not IPSC) to build muscle memory for high stress events (like gunfights).
I hate 1911's, personally, so have no idea if they are more prone to break than combat tupperware, but I guess Harley Davidsons do tend to run rougher than Hondas... Your mileage may vary.
I totally agree that if some 'tard were to just willy-nilly slam any of my guns around, I would taken them away, and never let them play again. As previously mentioned, it is all about respect.
I am pretty sure though, that if you've let your pistol slam closed on an empty chamber once or twice, it will NOT fall apart, as there is NO WAY your puny little arms are generating anywhere near the energies that live ammunition is exerting on your bits and pieces, when they slam back and forth.
My opinion, for what it may be worth, based on only 17 and a half years of carrying a pistol at work, and shooting recreationally whenever I can.
Cheers,
Neal