There ARE many, but I don't think that's the reason for this. A lot of people are constantly on guard about any stranger calling them out for anything. In that case, it's much easier to to say, "Who TF are you?" than "My fault, I didn't think of it that way", because a stranger calling someone out from nowhere raises an immediate red flag for some people, regardless of the specific issue being addressed. Obviously, you are right about the disrespect, but it seems like putting things down on Jazz's monument has become an accepted action, and with the hindsight of 20/20, I probably would've told someone in authority if that got my attention. But if I did decide to call out a stranger on something like that, I wouldn't surprised by a hard comeback and would be ready to "go all in" to support my conviction.