I don't know, they are referencing celebrity chefs... I kind of expected more parody here. It's not a necessary thing for Scooby Doo movies to work, but when you start talking about Celebrity Chefs, you at least expect a few digs at Hell's Kitchen... not to mention all the others.
If Ravencroft can be a thinly veiled parody of Stephen King... they could throw a punch or two at good old Gordon Ramsey.
The humor isn't bad, but, really, REALLY, you were expecting a parody in the same vein that they went after Aliens, National Lampoons Vacation, and so many others.
So in the end, it felt kind of flat.