It's a catch 22 for the airlines. Suppose they cancelled flights after a given period of time. Then passengers get to disembark but are stuck at their point of origination, possibly without a place to stay, and then perhaps fighting to get to their destination because everyone else who had flights cancelled is now trying to get to the same place as soon as possible.

Six hours on a plane with access to toilets and drinks is unpleasant for sure, and I wouldn't want to experience it, but hardly what I would call "obscene and inhumane conditions." Now without toilets or water, that's inhumane - and NW's poor treatment of pax last winter at DTW was one of the major factors spurring on Customers First.