Consider for a moment the opposite side of the coin.
My best man's wife buys her daughter a new car every 6 months - simply because she's grown tired of the old one (as if 6 months was old). Wifey coddles the girl in every way - paid for her to go to nursing school, but a year later she's not interested in it and now wifey is paying for her to get a second degree. Wifey pays her daughters rent and food, because a real job that would actually support her is too much a bother and too far away. Wifey, an adult, hangs on her kid's every word and when girly says jump wifey asks how high?
So now we have a 22 year old 13 year old, who's never going to grow up, or learn how to take care of herself, or become fully socialized, is going to cost her mom her retirement, and will eventually end up under a bridge when the day comes that mommy is no longer there to be at her beck and call.
You don't really want that kind of adult guiding you in your formative years, do you?
Geez, don't get me started about my sister in law's entitlement brat...