Why is kicking associated with a lack of honour or a street fight mentality?

It takes tremendous skill to throw a perfect kick, certainly harder than throwing a punch, and why exactly is it dishonourable?

In a real life street fight most people wear shoes so a kick to the face would b dishonourable since a nice steel toe cap or pointy shoe could be seen as a weapon, but in mixed martial arts the person is bare foot so are merely attacking with a limb just like using their arms.

Your analagy to art completely falls flat. Mark my words, if any paintings were discovered from Rembrandt or Da Vinci that were made in an impressionism or post impressionism style the art world would have a collective orgasm, it would be world wide news, we'd be informed over and over and over again just what visionary geniuses these guys were, anticipating an art movement some three hundred years before it developed and I guarantee those paintings would probably be some of the most expensive pieces of art in world history.