Intuitively, it is pretty clear that you spend more time going against the wind than with the wind for an out-and-back course, so you can't possibly make up the lost time.
Right, but what I'm saying is this (with really rough numbers):
No wind entire distance: 20 mph average.
Tailwind half distance: 25 mph average.
Headwind half distance: 15 mph average.
Total average: 20 mph.
I understand you will spend more time in the headwind, but you partially made up for that lost time (vs. zero wind) when you had the tailwind. The point I am making is that I underestimated the effect of a constant wind on an out and back course.