I was always offended when I was a nursing mom, to be relegated to nasty public restrooms. So I do relate to the problem of having to satisfy hungry babies at inopportune times and places.
But assuming you're right, that Mom had a demanding, noisy, "terrible two" little tyrant, and only nursed the child to keep from disturbing other passengers. I still can't buy the notion that a busy flight attendant (on a short flight), would have any inclination or motive, to maliciously reprimand a nursing mom.
I think we don't have all the facts.
Angry bitter feminists and lots of insecure men make nsty comments about breast feeding. I've had them made about me, while fully covered nursing a two week old baby. In a doctor's office.
People seem to believe that they have a right to make unsolicited comments to women who are nursing. Just like they seem to think that they have the right to make inappropriate and offensive comments to mothers with more than two children.