I watch people fight in a cage for a hobby, what they do in their own time isn't my business. If Jon was clean good for him, if he weaseled his way out of a drug test good for him and the fans. I think most "fans" live under this illusion that the pro athletes they watch on TV live lives free of drugs or performance-enhancing substances which is a pipe dream. Personally, I think USADA has neutered the UFC and if I was a fighter that fought top 5 ranked guys in a division I'd do whatever I could to make sure I win also. Whether you are greasing your body to avoid submissions, punching people in the dick, poking eyes, kicking peoples knees to gift them a knee surgery, there are still plenty of ways that are legal even for fighters to gain an edge in the competition.
The Paulo Costa and Uriah Hall fight comes to mind, that fight got stopped what 3 times? Two times for Costa slipping punches to Uriah's dick and another for Costa eye-poking Uriah. Then Uriah eventually got knocked out. Whose to say that was fairer or less fair than someone getting popped with picograms, kilograms or milligrams of steroids. Unfortunately, nobody cares what Costa did to win, they remember the TKO.