It may be easy to fight like Tyson, but it ain't easy to fight like Holyfield.The "punch" exists as part of pretty much every codified martial art I've ever heard of. Seems natural enough going by the evidence. I'll give you that hammer-fists are even more natural as an instinctive movement.
And a martial art. Going on from it's reintroduction to England by Figg, Boxing has been considered an unarmed martial art of self defense. Boxing is a "sport" in the same way that Judo and Tae Kwon Do are "sports."
But still easier than any other empty-handed martial art, however.
Peace favor your sword,
Kirk