"There is a difference between a cult movie with an actual cast & one centered around man eating sharks flying around on land. It is catering to the lowest common denominator. If it is your cup of tea, great. I will pass on it thank you."
The Roger Corman film did not start life as a cult classic though, and Sharknado may be on the path to becoming one. Everyone seems to be familiar with the film. It has been talked about and joked about on most of your talk shows. It has become a must see film for its sheer badness. In the coming years it will probably be bundled in one of those boxes of 20 cult films for $5 just like the Corman films.
This will likely be a silly and campy musical, but we have no idea whether or not it is truly sinking to the lowest common denominator until we see or hear something from it. I may pass on it as well, but I think more information is needed before we proclaim it to be garbage. Like you, I can be a pretty snooty person about all things theatre, but I would rather be snooty with reason.