Hollywood first makes trainloads of money on the real scary movies. Then they produce a parody on themselves, making a trainload of money again. Both the real scary movies and the parody is for a large part playing on attractive young girls and american teenage culture (or how Hollywood thinks all the american teenagers wish their culture was like at any rate).
My real problem with Scary Movie is that it tries hard to be a parody, but all the time it just uses the same tecniques even to sell the parodies. In my opinion Scary Movie is a parody on itself (and the whole consumer age lets-put-in-the-ingredients-that-will-make-us-the-greatest-bucks-mentality), in ways the writers possibly didn't foresee, but more probably didn't care as it paid their wages.
You might be saying that I have no sense of irony, that this is how the movie is supposed be, self-ironic. Well I'm not referring to that part of it. I think I handle most forms of irony, self-irony, double and triple and sarcastic irony well enough, Norwegian culture is full of it, ten times more so than US. It's just that that movie has many levels, and I'm just seeing one more beneath the admittedly funny self-ironic one. Which makes me kind of dislike it. (For the same reasons I dislike very many of the late Hollywood flicks, I guess I'm kinda odd in the movie department though, note I'm not telling any of you people what movies you are going to like though)