These movies are never mean't to be taken serious.
They are just fun films, not Oscar winning material like Citizen Kane.
I did a marathon with Sharknado l and ll for Shark Week. I called it When Sharks Emerge. You guys can look it up on the blog if you want.You can check it out here.
http://mbmb14.blogspot.com/2015/07/when-sharks-emarge.html