You would suggest that he denounce the actions of very dangerous people publically, half a world away where his family lives in order for wishy washy mma fans to feel as though they can back a guy for being morally righteous?
Sounds like a solid plan from a bunch of children who have no concept of how dangerous the world can be outside their own borders. When you are in rome, you do as the romans do or you end up facing the lions.
I am not sure we are in a position to really know what happens over there or how things work. It is possible that Khabib is a bad guy, it is also possible that he knows a bunch of bad guys who it would be very unwise to piss off, especially now that he is famous. I have not seen any evidence that implicates him in any crimes.