Our laws have alot to do with it. And The org. have to just live with those rules. It wasnt to long ago that the UFC was fighting in tents on the bank of the Mississippi because it was to brutal for people. I'm no Muay thai expert either, but I have read arguments before that the way the rounds, lengths of fights as well as the genneral fighting culture is in Thailand, makes it much more practical for their fighters to fight on a more regular basis.
Dont really understand the logic of the child prostitution remark, it seems like kind of a stretch.
I think the major thing is the mentality, MT fighters often have a more traditional martial artist mentality, meaning they are not going into the ring to disembowel the other fighter like MMa fighters often are.
With all that said, alot of the suspensions handed out for injuries are BS, and the fighters also used to fight alot more before the UFC got a stranglehold. EG. How many fights do bellator contestants have in a 3-4 month period, more than some UFC fighters do in a year.