I think its 100% a relation of how kid friendly the Crew are and cannot be generalized to an airline, although some airlines seem to offer more in terms of service and amenities than others.

I traveled solo translatlantic with my then 1.5 year old son with BA and found the experience very good. The FAs went out of their way to ask if I needed a break to use the washroom, and volunteered to take him for a few minutes. They also asked me whether to bring his meal first and mine later on. Lots of amenities were offered too such as games, puzzles, etc. Its generally the smaller, no cost elements that make the experience memorable or not. A friend of mine flew on Gulf Air and was praising their Sky Nanny program. The Middle Eastern carriers and some European ones seem to invest heavily in a kid friendly product and it shows.