Why do newlyweds put flowers on Kant's grave?

Kant is buried in Kaliningrad, Russia. Recently I learned that Newlyweds place flowers at Kants grave. It is a superstitiuous act done in hopes of a long and happy life. I searched every article I could find and I cannot figure out why.

My roommates suggested it might be that they like the travel distination and need an excuse to go there and a reason to cross the border. But that still means the tradition is being used as an excuse, and that it already existed.

My theory is that some people read a little bit of Kant and mixed philosophy up with spirits. Thinking he was a saint they proceeded to make offerings to him, and because he is not there was no trouble with them continuing. But that this theory is still somewhat unfulfilling, more then not because I have absolutely no evidence to back it up.