The thing to remember is Kinder adult to child ratio is different to Child Care. The other reason its an issue is due to the fact that if one of the carers has to leave the room to change a nappy (which can take 5 minutes) that means that 20 odd children are left to be cared for by one adult (and possibly a parent helper) where as child care mostly has a 5-6 children per adult ratio.

I personally think its good that there is a TT Policy. But I guess because I was told why it made sense.