Why are moves like hammer fists or spinning backfists illegal in boxing?

[sentax]

Common MMA moves that utilize only the hands in attack but why are those moves banned in boxing?

[lparm]

Boxers tend to more strict on basic fighting skills. That's the same reason why a great boxer would suck in MMA but not necessarily the same way around

[GGG Gloveking]

With a hammer fist, you're striking with a part of the glove that isnt padded. With a spinning backfist, youre turning your back on your opponent, which is forbidden in boxing and potentially dangerous

[NC Uppercut]

This is boxing, not MMA or Karate dude

[KingHippo]

Boxers tend to more strict on basic fighting skills. That's the same reason why a great boxer would suck in MMA but not necessarily the same way around

I'm 100% positive that a great boxer has a much better chance at MMA then the other way around. Boxing is a major skill in MMA. An MMA fighter would give up half of his skillset in boxing. Give a great MMA fighter one year of boxing training and give a great boxer one year of take down defense and tell me who does better.