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Think of it this way: If your ground speed is 200 mph, but you have a 100 mph tail wind, then your actual air speed is only 100 mph (200 mph - 100mph). If you have a 100 mph head wind, then your air speed is 300 mph with a 200 mph ground speed. The aircraft doesn't care what the ground speed is, only the speed of the airflow past the aircraft.

Ground speed has nothing to do with it. Once a part of the moving airmass, tailwind/headwind have no effect on the airflow over the wing. The real issue is that airspeed is a function of the density of the air, and as you climb into thinner air, your INDICATED airspeed is quite different from your TRUE airspeed (ground speed means nothing to an airfoil). For example, at 35,000' in standard conditions (15c, 29.92, standard deviation) 240 knots INDICATED airspeed translates into 450 knots TRUE airspeed. It is that efficiency that makes modern airliners work. There are other issues such as outside air temperature and compressibility (as air is compressed going over the wing, the temperature rises as does the air density).

Since the all the WING cares about is INDICATED airspeed (the real effect of the molecules moving over the wing), knowing what the INDICATED airspeed is at any given moment is vital to an airliner at high altitude, because the maximum mach number and the minimum airspeed are VERY close the higher you climb.

At 41,000 feet, on most subsonic aircraft, max mach and minimum airspeed can be within 10 knots of each other, and you fly between the two (called "coffin corner" to us old-timers). In other words, speed up 5 knots, the aircraft starts mach buffet and possibly comes apart - slow down 5 knots and the aircraft goes into aerodynamic stall, and plummets, at an altitude that makes recovery difficult if not impossible.