people do not expect to have to suffer discomfort from other peoples children and the price of premium class tickets acts as something of a natural defence in this regard
My only bad experience of this, which I have described before, was a "Third World" Ambassador's wife and their two children (not babies) in C class on EI Dublin - London, who treated the front cabin as a personal playpen, ran around screaming, overturned other pax's drinks, scolded the FAs who tried to control things, stole items from the cart, and generally were the Flight from Hell. Skipper should have put the seat belt sign on, but as they ignored it when it was put on for the London approach, would have made no difference.
Good to see our foreign aid to that poverty-stricken country being used in this way on these tickets.