Twelve is a quite high ratio of children to carer. In Sweden what is considered a healthy ratio is 5:1, and many places do meet that rate or are very close to it.
10:1 would be considered a very poor daycare, and most people wouldn't want to put their children on it — only if they have no other choice.
Regarding pay being bad this happens over here as well, unfortunately. Teaching in general is not paid as much as it is worth.