Boxing is inherently dangerous but no more so than several other activities.
I'm inclined to think about what the Boxers (and participants in other contact sports) would be doing if they weren't learning about discipline and fitness at their gym.
It reminds me rather of the "War on Drugs". It seems obvious to ban drugs and yet, counter intuitively perhaps, it makes the problem worse than legalising them, and having some kind of control over the problem.