I know in your post that you were trying to correct what was an unacceptable behavior, and that resulted in a melt-down. But I'm also guessing that your child didn't then cry for four hours. Most people will understand a short temper tantrum. But ignoring you child for hours on end and letting them disturb a plane full of people is not understandable.
You are right. He did melt down but he did not do it for 4 hours. I doubt he would ever had enough energy to melt-down for 4 hours without falling asleep. I just went back and re-read the original post. I noticed the OP mentioned it was a 4 hour flight but she didn't say the child wailed for 4 hours. Just that the parents were doing anything to calm the child. OP, just curious if you have a sense for about how long the child cried?
I'm sorry, but if you know ahead of time that you child can't handle a situation, it is up to the parent to not put them in that situation. Period. And that doesn't change because you have a special needs child. It has nothing to do with isolating a child, and everything to do with having consideration for those around you. Letting your child cry it out where it bothers a few hundred people who are unable to leave is unacceptable.
I wrote a long response to this, but when I re-read your quote I realized my response probably was not appropriate. I guess agree with part of your quote...but I suspect we have very different opinions on the situation. You wrote "If you know ahead of time" but really as an outside observer we hardly ever know if the parent "knew ahead of time" or not.
Places that I know are issues (like the local Target) I try to avoid. We didn't go to a restaurant for about 18 months when DS was young b/c it was not good for DS or us. If I knew ahead of time a situation would get be miserable....heck, yeah I'd avoid it if i could.
As for the part of being considerate of those around you...I'm all for that. But I also try to be respectful of my child. My DS has other challenging behaviors that might make it uncomfortable for other people, but I really don't think I'm doing anyone a service by forcing him to stay home. More importantly, I don't think I'm doing him a service by forcing him to stay home. And I don't want to live in a society where we exclude people with differences from our society. (And I made that decision long before I had a difficult child).
My DS from time to time makes noises. It must be pretty annoying to be sitting next to someone on a plane who makes noises (sometimes it will be 2 or 3 noises in a minute, sometimes it will be 1 or 2 noises every few minutes). Sometimes he can site quietly. Is it inconsiderate of me to take my DS on an airplane in light of this? Maybe, but like I said, in addition to trying to be considerate to others on the airplane, I also need to be considerate of my son. Continually excluding him from things b/c it's more difficult for him to participate is not respectful of him.
I suspect you might agree with that assessment in general, but want to draw the distinction at an "airplane". I think that airplanes raise their own issues. Yes, people are captive. But they have also chosen to use a mode of public transportation. It's easy to say "don't go on vacation to Florida" but we have family that lives at great distances (on the other side of the country) and visiting would impossible without air travel. Finally, if your qualification is "if you know ahead of time"...well, I bet there are plenty of kids who do ok on one flight and not so hot on another. I'm not clairvoyant. Thankfully, my kids do well way more often than not. (hope I didn't just jinx myself). I guess I suppose its easy to judge parents when we come up with hypotheticals where we know the whole story, but in real life we don't know the whole story. Just one little snippet of what we see. I try to remind myself that when I find myself judging.
Amy