That movie franchise only works with the Rifftrax. It is such a stupid concept and yet people seem to be willing to give their time and pride away for free, just for a little publicity. And then people watch it because it is so stupid. I thought that was what Star Wars VII to IX was for.
I don't think it's meant to be serious...it's gotten to where half the fun of the SN franchise is spotting the cameos.
Correct, it isn't trying to be serious, and people have made movies like that, they are called comedies. Airplane! isn't "serious", but that didn't mean the Zuckers and Abrahams didn't have to have good jokes, gags, and viable plot. Airplane! is ridiculous, but you still cheer for Ted Stryker. You actually care about the characters, despite the silliness.
Sharknado, the jokes aren't funny, the "action" is campy, the concept is ridiculously stupid. What makes good comedy is that either it is an absurd action in a real world (girl scouts start a bar fight), there is a developed narrative (visual or script) for the joke (guy getting mauled by dog at Captain Krammers' house), a running gag (it's a building with doctors and nurses, but that isn't important right now), or simply a joke or visual gag (Nielsen walking in on stewardess trying to blow up the auto pilot).
Just because something is stupid, doesn't make it viable (see Family Guy Season 4 and onward).
Sharknado is stupid, real stupid. It isn't edited or filmed well. The jokes aren't remotely funny. The characters are less likable that the general population in Grand Theft Auto. The plot sure the heck is too ridiculous that it becomes impossible to reasonably resolve it (bombs in a tornado?!). And when everyone is a cameo, the cameos get old.
Fuck Sharknado. Goodness, I took way too much effort to put the Internet right about this.