If an able-bodied pilot had found himself in the same situation because he'd got cramp in the hand that was holding the control column would the same people be calling for his licence to be revoked too?
Would cramp affect the pilot instantaneously, rendering him suddenly unable to control the aircraft? This risk has been discussed amongst private pilots flying light aircraft solo, with sidesticks, on long flights, but the effect will build over time and the availability of an autopilot is one mitigation response.
The problem in the Flybe incident was that an unforeseen and catastrophic failure mode occurred (catastrophic in the sense that the prosthesis detached suddenly and could not be reattached in time to complete the landing.)
Now the failure mode has occurred, I am sure that lessons have been learned and response plans put into place, including briefing etc.
I am not calling for the pilot's medical to be pulled.