I think it stems from jealousy. Its like the guy who invented the hula hoop. Its pretty damn simple, didn't exactly take an engineer to design, yet no one had done it before. Since it was successful it pissed people off because they could well have thought of it themselves.
This is why people get upset with Katz, he makes a lot of 'obvious' observations. He might not even be the first person do make them, he just recognizes their importance.