This seems a very reasonable policy to me.
The injured are not being
obliged to leave the armed forces - they are being
encouraged to do so. In other words, they are being provided with rehabilitation, retraining and resettlement assistance so that moving on becomes a more attractive proposition than staying.
For those who still want to stay on, they can do so if their injuries are such that they are still capable of fulfilling other roles in the military.
I think it ironic that, given some of the outrage expressed on this thread, that there is a concurrent thread
here where contributors are moaning that a 100k bonus is not enough incentive to make them stay on as aircrew, and how they can't wait until they can get into the airlines and earn more, even though HMG has invested several million pounds in their training already.