I think if this person does not become agressive outisde of the ring (which was very often in Russia in eraly 1990s when young boxers and wrestlers sometimes prefered to become a member of a gang to a pro-athlete), is ok. I think that hunting (not for food, I myself eat meat but for entertaimnent) is much worser. I am here totally with Lady Diana in her famous quarrel with the Queen .
In fact, not one use broken glass on the gloves or something like that now, so the peoples' longing for some agressive show becomes more civilised in the last 100 years anyway.