If you believe the narrator, Irish parents would be downright grateful for a chance to get rid of their babies. After spending a year fattening up their flesh and blood, it stands to reason that they'd be happy to earn some cash.
The most important role the parents serve is as breeders, the narrator says. In fact, they're described suspiciously like cattle. The narrator is particularly specific about how raising kids for food would impact a marriage:
Men would become as fond of their wives during the time of their pregnancy as they are now of their mares in foal, their cows in calf, or sows when they are ready to farrow. (25)
It seems the Irish would be more than happy to say sayonara to their toddlers, and not just because they're whiners; the kids won't have to suffer through misfortunes like starving or getting kicked out by greedy landlords.