Runway behind you - a way to save time?
I was a bit surprised very recently to find myself in the back of a 738 with 170+ pax taking an unfamiliar and hesitant taxying shortcut to a point 2300 feet down the runway (estimated from Google Earth). The take off roll was approximately 35 seconds and we rotated after about 4000 feet of roll with 1800 feet of runway remaining after the wheels left the ground (some 30 minutes late on final sector of the day I might add).
For what little time and fuel was saved in missing out the usual additional 2300 foot taxy, I personally would have preferred to have left the ground with 4100 feet remaining.
I have always believed that runway behind you is one of the most useless things you can equip yourself with before committing aviation.
Am I being unfairly critical?