The problem lies with the fact that the issue is handled by the U.S. Anti-Doping Agency (USADA), not the UFC. Since USADA stepped in, a number of fighters have been flagged for violating the anti-doping policy. While some have been popped for minor infractions, other have been caught using agents of anabolic steroids.
During the UFC 217 post-fight press conference, White talked about the length of suspensions handed out by USADA (via MMA Weekly):
“I don’t disagree with that, but USADA deals with that, we don’t. We’re out of that business. We leave it to the professionals. But yeah, I don’t disagree.”