Earlier quoted context omitted.
It's true, and makes sense where your face-to-face time is the key thing. But where it's just "work time", surely you can do a good amount of work on a 7 hour flight in a decent business class seat with reliable internet? Especially if you can also minimise the time wasted on the ground (fast security line, lounge with areas to work, airline calling your flight when it's almost finished boarding not at the start, etc…
There are definitely people who can get work done in a flight, but honestly I have a hard time imagining logging 7 hours. Maybe if you have a lot of reading to do?
I think if I had a decent internet connection (happening more and more) and comfortable seat I'd happily take a 7/8 hour flight over a 5 hour one in a coach-style seat.