Disposable nappies are partly to blame:
The key to potty training is for the child to associate the sensation of needing to go to the toilet with the result this produces.
But nappy technology is so advanced that the fabric in contact with the skin simply wicks away any dampness or discomfort, and the child obliviously carries on with his or her activities.
I am hoping that potty training will be easier to deal with in cloth.