If they made the comedy subtle, then it would have been a satire and very VERY few satires in film form are ever popular.
The thing is Scary Movie was a parody of Scream, which was a (rather popular) satire of the teen slasher flick. The levels of meta are astounding.
For the record: I liked Scary Movie 1, thought Scary Movie 2 was pretty boring (but to be fair, I was never a fan of the Haunted House genre), and laughed one time during Scary Movie 3: "...and now the killer video that kills you seven days after you watched it, we're the only station that has it and we are showing it all night." This is funny because it is something a station would actually do. For reasons unknown, I saw Scary Movie 4 in theaters, and the only time anyone in the theater laughed was when one of the characters said "Ima put that on MySpace."
"Meet the Spartans" is a movie that could work. Well, the idea of it parodying 300 and by extension, Frank Miller (Like, they could have a little counter in each corner that keeps track of how many female characters are raped and/or become prostitutes) could work, but instead, we get stale pop culture references that aren't even jokes or insightful.
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Oh. My. God. This is pretty much 4chan: The Movie, isn't it?