What's with all the hand-wringing about the state of genre YA?

The SFSignal posted an article today about the lack of superheroes in YA by YA author KD McEntire:

Why is it that, with all this room for self-expression, with all this space for examining the nooks and crannies of the human (and non-human) condition alike, that you hardly ever see a single Young Adult title sporting a spandex-clad super human? Why are the epic battles that could be spun out between super-powered beings confined to the realm of sexy vampires and sultry witches? Do we really...