Why don't gymnasts have to wear shoes? All other indoor sports wear footwear, why not them?

My guess is that they're better able to feel the ground/balance beam. If they have shoes on, they wouldn't be able to know exactly where their feet are on the beam, which can be devastating. Also, gymnastics as an artistic element to it, and the pointed feet adds to it just like in ballet, but they don't need hard, leather pointe shoes).