Good points, all. I particularly like the pizza vs teriyaki metaphor, particularly if you extend it to the point where a pizza joint might try to make teriyaki, but chances are it isn't going to be very good teriyaki. Better to go to the pizza parlor for pizza and the Japanese restaurant for teriyaki. Both of which are delicious, but very different, requiring different skills to prepare well. (I actually think it's a more apt metaphor than the film genres.)

I confess that I have a hard time taking the Critical Media Theory hat off, especially when I'm talking with people that I know are capable of wearing it, because I find that kind of analysis both interesting and valuable. But I know, in theory, that it isn't always appropriate.