They don't make the movies. They just make fun of them!
Go ahead and buy a couple rifftrax and try them out! They're powerfully hilarious and only cost a couple bucks a pop. It'll be the best couple bucks you ever spent.
And if you are unfamiliar with the whole concept, rent a couple Mystery Science Theater episodes and get hooked. They will rock your uvula. I mean it. This is funnier content than a whole month of TV comedy writing. I mean, funier even than what is considered good comedy writing. "MST3K" was the comedy show that comedy writers themselves watched and loved.