I can recall having to explain to her WHY she should bother to become toilet trained. Truly not kidding; this was a very striking example of something that she saw no particular benefit in, and felt was more about OUR desires than hers.
Dealing with this right now. DD is going to be 3.5yo in couple of weeks and is still not potty trained. I have tried all the tricks in the books on motivating her but like you say, she clearly sees this as a discomfort to her and a benefit to us, so why bother. When I lament about how other kids her age are potty trained she simply says," I know, Mom, I know. I am sorry I can't stop using the diapers and start using the potty. But I am just not going to do it."
