Clearly, the military has set standards of physical condition and injuries and disabilities. That has been tested over many, many years. If your military occupation demands a certain physical state, then if you don't meet that, you have the choice of either being transferred to another occupational area or being released. I can't put any sort of qualitative statement on that. In my opinion, the system does appear to work.
Now, it is traumatic to leave the military. After 35 years of regular force service and with 15 years in retirement now, almost every night I still dream about being in the military.