Vessbot
I meant that if you see, say 250 GS at FL350, and you have a stall warning, it might help to recognize a stall. If a crew is mislead by multiple failures, Ground Speed is there to give an independant speed data.
When GS is not on PFD, it is not in the primary scan. I am wondering if this could be a contributing factor. Like the side stick thing : proper design ?