I think the lesson she was suggesting is the lesson that pooping yourself is inappropriate. Not a lesson we all teach. I do.
All of you who are critical of having expectations of one's children that they will start using the potty when they are able, examine if you don't have similar etiquette expectations for your child. E.g., you don't eat yogurt with your hands when you're old enough to use a spoon, you take off your muddy shoes before you track through the house. I'm not sure how different it is to decide that you want to channel your child to eliminate in potties or toilets.
We all pick our battles. I don't, for example, worry about water tracked out of the bathtub. Saves me energy not worrying about that. I did PL early. Not nighttime ... I wait for that to come on its own. Not naptime ... I wait for that to come on its own. But my kids PL'd earlier than any of their friends I can think of. Why? Took away the diapers, that's why. Bare bottom'd 'em. They weren't punished or ridiculed. They did have to help wipe up accidents. It's their eliminations, not mine. Pottying is a dignifying activity, not a degrading one. They were enabled.
So my son's diapers went away in June. He's now 19 months, and he probably has one accident a month in the house, and it's a little slower than I'd expect out of the house because his other significant people are less committed and let him use a pullup as a diaper out of the house. With me? He's good out of the house. He trusts I will get him to a potty when he asks for one.
I was in diapers as a three year old. My mom picked other battles. She just didn't want that one. To each her own.
I found that by doing it young, we had no battles. Diapers gone. If they're young enough, they don't look back so much.
know what she did? held her urine so long she gave herself a uti complete with fever.