Do you know Peter Singer's parable of the shallow pond? Why is what you are puzzled about any different than asking yourself why you haven't donated everything you have right now to save lives in undeveloped parts of the world?
In my mind it's like an off-duty firefighter standing next to someone unconscious in a burning building and being able to easily drag them to safety, but deciding not to because it might give them back problems in a few years. It's an emergency, they know how to fix it and can do so easily, and the sacrifice is minimal compared to the danger.
Pretty much your whole justification is that they've happened to invest in medicine and intentionally positioned themselves outside the burning building. You're investing in what? Yourself? Thin soup.
I get where you're coming from but people are just selfish with money, it is how it is.
Most of the threads I've started have now devolved into people accusing me of being a hypocrite who's never sacrificed anything in my life, so I guess that's the end of the road. I still don't understand why anyone needs to be convinced that this obvious moral choice is a good thing to do, and I guess I never will.