If the latter, sorry I misunderstood what you were addressing.
But otherwise this isn’t a punitive thing where we’re measuring how wrong they are and their mental ability / level of guilt before acting. It’s a temporary and immediate solution when the parent can’t handle it on their own and the staff talking to them isn’t mitigating the risk.
The idea is to choose the safest and least violent viable option until law enforcement can handle it (choking someone… eh not so much).
Absent ‘alternative means’ provided by the airline, duct tape is one of the quickest, most widely accessible, and probably most practical if non-violent options all fail. Not everyone carries rope or other restraints. These are civilian airline workers too.
Restraining someone can have a legitimate mental impact and bad PR but so does the rest of the passengers who are all naturally scared of plane crashes.
What about this being a 13 year old is mitigating in your mind vs a middle-aged person?