I think Marijuana is still not legalized everywhere in the world because the tobacco industry doesn't want it to be. It has less adverse effects than tobacco and no performance enhancing effects.
Therefore I have nothing against athletes who use pot, just don't get high an hour before the competition starts.
edit: ^It seems I kinda stole the beginnings of my sentences from you.
Agree with this. Also big Pharma companies don't want it legal either. They want to protect the millions and millions they make off pushing dangerous pain killers on people. It is all about who has the money and who lobbies the hardest for what they want.
Instead we keep it on the black market where teenagers and all people get to deal with drug dealers who not only sell weed, but cocaine, heroin, meth...It is odd that they have a "war on drugs", yet by not regulating it they are basically saying "here gangs and drug dealer, you keep making money off this product and we will pretend we are so against the violence that comes with you guys selling it".
Makes no sense. But as long as U.S. federal law has it as illegal, then UFC or any sport will follow suit. They sort of have too.