Rudeness is bad, the guy indeed misbehaved.

That said, I am not a big fan of babies/children flying in J or F. When they are toddlers I think the risk of disturbance to other fellow travellers is too high, while when they start growing up I think letting them travel premium is not exactly a formative experience as it risk to establish the idea that a lie flat bed and lounges are to be taken for granted.

Premium Economy is the perfect compromise for premium family travel IMO.