in my single days (and later in my living-with and married pre-parental days) I had three criteria for tolerating children under about age 8 on planes: they had to be quiet, they had to be at a reasonable -- at least one row in between them and me -- distance, and they had to belong to someone else

once the child in question was mine (i.e., once I was on the receiving end of glares and grumbles, even though my son was a very tolerant, patient, and well-behaved traveler in his early years) those criteria vanished

a little bit of respect for others, and a little bit of common courtesy, go a long way in situations like this