Actually, you are wrong on this regard. One can easily document a handful of cases to people carrying out a hoax. However, while one can explain how a human could create such, it has been demonstratably obvious that it would be rather impossible to put together such in a single night using only simple tools and handful of conspirators, such as would have to happen in order to explain said circles. A "rational explanation" is not the end of the phenomena. Crop circles are a sign of intelligence, but not human in origin.
Heheheheheh, nope, I can't go there.
A few years ago, there was a collection of amazingly intricate designs, widely heralded as proof!
The hoaxers later stepped forward. They'd documented everything, and put up an extensive website detailing it all.
It's not as hard as it looks. And there are a lot more than a couple of college kids here and there doing it.