“You used to be a child once, so you aren’t allowed to be frustrated at any behaviours of children or choices of their caregivers” sure is a perspective.

Yes, I was once a child. And if my parents had taken me on a flight before I was sufficiently mature not to yell during it, they would have been being irresponsible and selfish. “Babies scream, sometimes there’s nothing you can do to stop them” is true, but doesn’t imply that you should be allowed to take them anywhere.