If you are asking if cures for HIV/AIDS, cancers, Parkinson's disease and spinal cord damage would upset the economic balance of the medical profession, the health insurers, and the employment market, the answer is that it would probably not. There are many other conditions which remain to be cured. The medical professionals would not suffer a loss.
There is enough human suffering without people having to live and die with these conditions. Many excellent minds to save, money which could be spent in other ways.
If you are looking for a moral imperative because you feel that these conditions are punishment for some sin of the person or of mankind, I would only respond that disease and injury whether incurred through carelessness, heredity, toxic exposure, accident, randomness, injury are just that. Avoidable only in hindsight in the majority.
Many people with these conditions can have a fairly long quantity of life, it is the quality of life which is difficult., stressful, painful and certainly affects those around them as well.
If these conditions could be "cured" think of all of the orphan diseases and other human suffering which could then be addressed.
Personally, I would love it if my husband's PD could be cured. If he could exercise - not to try to keep from losing even more strength - but to build strength. If he could have a life which was not made more difficult by the side effects of medications. If we didn't have to spend as much money on medications and supplements. If his tremors didn't profile him at the airport where he is subjected to the humiliation of full body searches. If I could tell whether he is making a wry joke or being serious. And he would love to be able to return to work where he could feel more productive.
Ask each person who has one of those conditions how they would feel. Ask their family and friends.