I've never seen pax complain about a crying baby, which makes me wonder if this was more of a screaming baby. You know the kind of crying I mean, the ear splitting wailing. In that case, I can't really fault anyone but the parents. I wouldn't care for any passenger to be screaming in my ear for the duration of a flight - that goes for adults, babies, or service animals or whatever.

Simply put: If you're causing other people discomfort that is your problem, not theirs.