Problems faced by foster mothers and natural mothers are astonishingly similar. The conclusion that motherhood in general requires little skill implacably follows. Look at the lack of realistic preparation in North America for domesticity in the form of supervised training. The implication is that any one can do it with few if any qualifications. Look at the lack of prestige of those courses which do attempt to provide this kind of training.
Pride is a function of prestige.
The innovation of a salary can do something more. A salary can be instrumental in breaking the exclusive association of women with domestic labor and child care by attracting men into the home. Sheer altruism won't motivate many men. A salary changes the situation and acts as a definite drawing card. Bingo, prestige rises.