The problem has become so widespread that Education Queensland is drawing up a toilet-training fact sheet amid calls from teachers' groups that nappy-wearing children be banned from attending school.It seems that these days there are a lot of things that parents can't be bothered teaching their children. Toilet training is only the beginning. There's manners and acceptable behaviour, like not behaving like feral banshees.
School can enforce manners and support good behaviours, but if it isn't happening at home it's not going to work.
You can't expect teachers to teach all the things they have to teach to kids now, and then some, and also change their nappies.
(this post was misplaced. h/t SandiM)