I suspect it's a practical concern if nothing else, having to do with mundane constraints like carry-on sizes. Also, as another practical matter, I highly doub

I suspect it's a practical concern if nothing else, having to do with mundane constraints like carry-on sizes. Also, as another practical matter, I highly doubt that the folks with severe air travel phobia would be even remotely trained to use a chute (which requires doing it, more than once!)