Yeah, I'd be seriously ticked off and I would complain to the parents and the airline if I had a child (any age) that disturbs me in business or first class. The reason that people book those seats are manifold but two of the main reasons are quiet and comfort to relax and/or work. A crying child interferes with two of the main functions.

Normally, the FC experience is selective enough by price, but unfortunately there are those wealthy enough AND inconsiderate enough to buy a full FC seat for a baby and think it's ok to do so.

Even if I had that kind of money, I would still not take my baby into FC or business class out of consideration for the other passengers. In fact, I would try to avoid flying with a child that might possibly be obnoxious, unless it is a real emergency. The only things that would count are family reunions due to death or medical reasons within the family. The only non-emergency I can think of is a long distance professional relocation. I would also not take a child into a nice restaurant, a library, a concert or any other venue where it might disturb others and where quiet can be expected such as the premium cabin of an aircraft.

People who do that are thinking of their own comfort much more than that of others. That's normal but not to this extent.

Sorry for the rant but it just needed to be said; unfortunately.

Till