Not sure the US airlines could make air travel any more painful than they already have. They have sucked the lifeblood out of air travel in a needless race to the bottom. Flying on low budget airlines in third world countries is a far superior experience.
When I travelled to Tanzania, I flew via Amsterdam (no time to explore during the layover, unfortunately), on a US carrier (United, I think) from Seattle, and on Royal Dutch from Amsterdam to Tanzania. The difference was shocking; the Royal Dutch flight was a LOT nicer; better food, more drink options (complimentary), more pleasant seating, and so on.
I suspect that the only thing keeping the European based airlines from taking over US domestic air travel from the US-based airlines is the federal government's protectionist laws that don't allow them to. The service on non-US based major carriers an on smaller regional carriers like Alaska and JetBlue and Virgin America have for years been quite a bit better than on the likes of Delta and United.