Because if I wanted to watch commercials I'd pay for cable and get a DVR to fast forward through them. Sure there are commercials on most cable TV but that is because there is no alternative. If hulu turns into a cable tv provider there is no compelling reason to choose them over cable/FIOS. Also I've been told that Netflix currently offer unlimited streaming in HD for a pretty low price commercial free.

That might be true, but those people are frankly stupid.

Ha, that seems a little strong. I know lots of intelligent people who purchase cable.