I don't see the big deal -- it's made to put on burgers and shitty sandwiches and is, without a doubt, the only cheese you can use for a grilled cheese and NOT be an asshole. It's not for eating with wine and appreciating with your fake-ass refined palate. Think of it in reverse, would you waste an awesome greyure on a fucking grilled cheese sandwich? Doubtful.
I constantly see people bitching about American cheese on the internet and I don't get it at all. It's good for certain things, and necessary for a few things, but it definitely isn't something worth getting pissed off about.