It would help if the more frequent traveler's in Group 1 understood why parents react so strongly to being separated and why we think it is idiotic that a computer program can not link a child with a parent so that in those cases where rearrangements are made they are kept together.
1) Instinct. The mommy radar is active at all times. 24/7 Like I said in a previous post it is my job. If I don't know what is going on I can't help/fix/change their behaviour.
2) It is the law. Can't leave small children unattended in everyday life. In the car, at the library, at home. It is drilled into us that you don't leave your child unattened anywhere. "Megan's Law" for one example. It is one of the reason's new flyer's are so shocked and thrown for a loop when it happens. Everywhere else it is illegal.
3) Cultural. I would never expect other parents to have water for my child at a soccer game. I am expected to register my children for school not have the school district hunt me down etc. The little girl that was swiped a couple of weeks ago walking just a few blocks home. She was unattended and one commentator went off on the parents.
With all due respect, you should have said "why SOME parents react so strongly". What makes you think that we don't have children? (Well, Bavaria doesn't, AFAIK, but I think that all of the other frequent fliers that have been posting on this thread DO have kids.) I'm rather well-known around here for flying nearly as much with my kids as without them, and they have been racking up airmiles since infancy, as I have a lot of family overseas and elsewhere in the US that we often visit.
1) My "radar" is quite fine. I try to have it re-tuned at least once a month so that it doesn't emit false alarms.
2) Well, it actually *isn't* the law in most cases; though TV has made us think so. (Trust me, public libraries deal with "drop-off" kids every day.)
NO ONE on an aircraft is really "unattended", because there are Flight Attendants. Also, these days, there are also lots of very snoopy fellow passengers who are imaging terrorists around every corner -- there are eyes upon you at all times.
3) No one is going to be able to open a hatch and throw your child out, so she won't disappear. In the case of a healthy child, the worst thing that could happen on an uneventful flight is that someone might grope him or her, but the odds of that are VERY low, for the reasons I stated above -- it would just be too risky in such close quarters with so many witnesses and no way to run.
The simple rule is that if you are separated from your child on an aircraft, the parent should always take the seat furthest aft, so that the child's seat is in front of you and you don't have to turn around to see what's going on there. You teach the child to ring the call bell if there is a problem, and you keep an eye on the row and be ready to get up and go up there if you see the FA called to the row (you can tell if she's been called, because she will reach up to deactivate the call switch.)
As to the water, at 6 there should not be any expectation that some other passenger needs to provide water, etc. That is what the Flight Attendants are there for, should such a need arise. The average first-grader should be perfectly fine managing her own snack on an aircraft, as presumably she does it in school every day. You put her in her seat and you hand her her bag of personal entertainment/snack supplies; and she'll manage from there, knowing that she can call the FA for help when needed.
WHEN a separation situation happens, if it happens, you will know at the gate. That being the case, when you find out, you make it a point to make sure that your child is prepped. You take her to the restroom. You make sure that she has what she needs in her own bag (and you go grab a plastic bag from the newstand if necessary.) You give her quiet entertainment, a water bottle, a snack, and some napkins to clean up with. You put earplanes in if she needs them, and you explain about when she should call the FA if there is a problem. You remind her to keep her hands and feet to herself and to use her most polite manners. Then you sit her in the seat, make sure that she knows where the call button is and that she has fastened her seat belt, and then you progress on back to your own seat.
I don't get separated from my younger child because we always use a carseat on board. My oldest is now 12, and over what is probably close to 200 flights, he's been separated from me maybe a dozen times since he was 5. It has never been a problem for either of us. He knows that I'm behind him and have my eye on him, and he knows that I will be all over him if another passenger or the FA complains about his behaviour. I also make him tell me where his exit is before I go to my own seat -- counting off the rows. (Everyone should do this every time they board a plane, because if it is dark you will have to count the seat rows to feel your way to the exit.)
I do, of course, look for possible seat trades and leverage my best seating assignment if it happens, but in every case, we both board the plane prepared to sit apart if need be. Panic or anger reactions are a serious waste of time and energy in this kind of situation.