The thing with stereotypes is that, while they tend to be well enough based in fact for most people to recognize, they are no better than anything else at applying generalizations to large groups of people. Some will always be unfairly targeted by them. You personally might not have done anything to contribute to those things we are lashing out against (and if not, thank you!), but then again you personally were not targeted by these remarks. In the same way that you are possibly unfairly swept up in these assertions, it is, to a degree, unfair for you to use your wounds to deprive the rest of us of freely voicing our well-founded grievances. Problems must be recognized before they can be addressed, after all, and collectively so for anything so widely spread. It's never pleasant to be told to "just tough it out", but perfect solutions are rare when people are involved, just as how surgeons have to cut healthy flesh to remove the unhealthy.

An analogue to this would be "all cops are bastards". Sure, there are some good ones out there, but there are enough bad ones out there that the stereotype generally applies. The statement is a rallying cry for something to be done about it. The "guilty by association" bit that tends to follow is another thing entirely.