OPENDOOR, I figure good sense disagrees with your rather broad statement. The inertial system can tell if the plane has actually decelerated or accelerated by over 200 kts or even 50kts and the mother of all tail winds overtook the plane. So there is a valid software check on the stall warning.
Furthermore, AI seems to think there is enough information in the inertial and GPS systems to keep the plane flying while the pitots recover. The plane has a tremendous amount of inertia. So one minute or less of simple pitch and altitude with comparison between inertial/GPS data on ground speed can diagnose whether they are in a large wind or not. If they are in a savage tail wind they will cover more ground than they should for the past ground speed. The difference is the speed of the tail wind. The same fits for any other strong wind. If you are not deviating from the previous course with no control changes then your airspeed cannot have changed.
It appears on a closer look that my naive question from a couple years ago has an even better answer than I'd thought at the time. It may give a bumpy ride for a couple minutes. But it will keep the plane going very nicely. It can tell you if you did hit a wind, what you need to do to correct for it. And the inertial system should be able to tell you quite rapidly what is going on.
However, the GPS alone is indeed useless. It's lag is too large. It can be cozened into giving you real velocity figures. The accuracy may not be as much as you like. (Three GPS antennas and differential phase tracking GPS can give you plane attitude, on large planes, fairly accurately, too.) GPS's main fault is that it tells you where you were not necessarily where you are. That's why you have Kalman filters and inertial navigation systems in the picture.
(And, yes, bienville, I do have a half a notion of what I am talking about with GPS.)