Daniel, I understand, and part of me feels the same way. It seems they are being "punished" for getting wounded. But it's my experience that the "fixes" to these situations usually ends up worse than the situation itself.
For example
During Desert Storm the press made "controversy" out of the separate rations policy. They pressured Prs. Bush and the pentagon to not only change the policy, but "repay" the soldiers for the separate rations not paid.
The "scandal" was further blown out of perportion when the press brought up how soldiers in military hospitals were being "charged" for their meals because the separate rations weren't being paid them.
When the dust settled, the pentagon decided to "repay" the soldiers. So, basically they were paid for food AND given food. Which means that some soldiers who served got a raise in pay that other soldiers (those ineligible for separate ration pay) weren't given. What made it even worse, some soldiers who were eligible were given the "repayment" while others weren't (there were explanations for this, but I don't remember what they were).
So nothing was "fixed" (because nothing was broken), but some soldiers did get a windfall lump sum payment for really no reason at all.
The fact is, there are a lot of reasons why soldiers entitled to a re-enlistment bonus might lose it through not fault of their own. If they got a bonus for a certain MOS, and that MOS is discontinued; if the rules for an MOS get changed, and that change makes the troop reclass (this happened a lot in the 90s when the rules were changed and colorblind people could no longer serve in Intel MOS's. Colorblind troops were reclassed, and bonuses were recouped.
Equality isn't Equal and Fairness is Never Fair. Yes, there are times when the rules need to be changed, but when those changes are demanded out of "fairness", almost always they end up doing more harm than good.