I have absolutely no problem with people expressing disappointment, I think that the occasional expression of disappointment is vital to a healthy relationship.

but, hm, while it was an over-the-top reaction, if it makes a few more people think about over-generalising from a particular set of circs, great.

Agreed. But the more over-the-top the reaction gets, the more likely it becomes that people will go 'I wish those people would shut up' instead of trying to understand.