No one's really gone after JDS legs, and Overeem has the ability and smarts to try.
I still agree though that JDS is the favourite if not only for the fact that he's the undefeated champion with a wake knockouts behind him in the UFC no less, but also that he would probably get the better of Overeem in a 5 round fight. Overeem has many accomplishments outside the UFC which are hard to qualify, and he has a more spotty record in his past.
Would love to see that match happen.
Just want to add that its not like JDS doesn't know how to throw a kick. He trains Muay Thai, he just chooses not use his other weapons that often, I imagine because his game is tight as it is now.