Parody Movies possess a long tradition throughout movie history. They also have a tradition of not being like by critics. Even Space Balls, a film beloved by millions of fans was only given 2 1/2 stars by Roger Ebert. Getting 3 stars for any parody movie is considered an achievement and also the last parody movie which had done so to my recollection was Scary Movie which received 3 stars by Roger Ebert. Naked Gun is considered almost a masterpiece at 3 1/2 stars.
My favorite parody movie as of late was Superhero Movie but that was not reviewed by Roger Ebert. I thought that the first Forty-five minutes were brilliant (especially the spoof on Spider-man's origin) but the last part kind of abandoned spoofing movies and went on it's own plot. Tropic Thunder was a borderline parody movie and that received the achievement of 3 1/2 stars. It's borderline because not really a large number from the movie was spoof material, it contained only small homages in some places.
I think which may be where spoofs will need to go in the future. Have a movie like Satisfy the Spartans. It essentially takes the movie 300 and adds gross out blue humor. The reason the film am bad was that it based the jokes round the need to rigidly follow the storyline of 300 rather than drawing from the larger source material and finding things that were funny.
Great spoofable moments in movies like "You Can't Handle the Truth", the death scene in Robocop 1, the twist at the end of The typical Suspects, Rosebud in Citizen Kane, the love scene in From Here to Eternity, and Arnold moments happen to be spoofed numerous times and that i never get sick of seeing them. If your movie is spoofable there are always new twists that may be put into make a new spoof of it original.
The problem that movies like Vampires Suck has is that it feels the need to pander to the audience because it wants to be considered a commercial success. It's trying to take advantage of the prosperity of the twilight movies rather than trying to take advantage of the success of being funny. Pure parody movies must find their success on videos where devoted fans can appreciate obscure references.
parody videos
The initial Austin Powers movies found the majority of it's success on video among fans who can appreciate references to movies that didn't emerge 5 minutes ago. The other ones didn't achieve this mainly because they began to pander to the audience.
Good pure spoof movies will need to go direct to video to allow them to be matched with fans who are able to appreciate subtlety. Movies with the odd spoof here and there like Tropic Thunder visit the giant screen where less knowledgeable moviegoers can appreciate the film for it's own merits.