I think the people that disagree with Mr. Kotick don't like his comments because they don't like people bragging about how much potential and how much money a product could make. The comment sounds too outspoken for them. His comment is merely a business viewpoint of his product, it's not like he's going "AHAHAHA GIVE ME ALL YOUR MONIES SO I CAN BECOME RICH!" to his customers. Here's what he's basically saying in a more user-friendly tone:

"Our Guitar Hero is doing very well for Activision right now. With online downloads and extra peripherals we can turn a product that used to only cost $50 into something that could possibly make hundreds of dollars for Activision, which would continue to make your favorite Guitar Hero games. And it gives you a better experience in the process. Nobody wants to play Guitar Hero with a controller right? That's why we make the drums. Don't like the song selection? Download different ones off of the PSN network"

Now nobody would have a problem with that statement like that which says the same thing, in a more consumer-friendly tone now would they?