And what "evidentiary vein" is that?
One theory can be more scientifically evidential than another based on quality and quantity of evidence but neither is anything more than a basic assumption and a lense through which the facts are viewed.
There is no "Theory of Creationism". It isn't even remotely scientific. Evolution, on the other hand, has loads of scientific evidence behind it. Just becuase you don't like it doesn't mean it isn't there.
Why should creationism be taught in schools when it isn't even a scientific theory?
The design and order in the universe is part of scientific evidence of a creator. And so the theory goes.