While you make a fair point, my guess is simply that AIRSPEED is the speed by which flying operations are conducted.
It is the BIG number in the instrument scan - much easier to see, while trying to maintain control of an aircraft, than a GS or wind indicator over in the corner of a flight display. It is THE number drilled into pilots as the critical thing to watch.
Especially in an abort, I'd say asking a pilot to divert any amount of attention to searching for a minor GS gauge, or doing math in their head ("Hmmm, we are doing 90 kts on the big gauge, but the headwind (the last we heard on ATIS from 20 minutes ago) was 30 kts, so our GS is now 60 kts and we can kill the reverse.") when there are bigger fish to fry (like stopping the plane before the hard stuff runs out) is inadvisable.
And I'd bet that is Boeing's reasoning, also. The KISS principle.
I guess a PIC could include such calculations in briefing a potential RTO or landing ahead of time, while calm and collected.