A guy can get up on stage and promise to save the world pretty easily. Investors, however, have to live in the real world where they actually have to manifest the promised tech. If they don't think they can, well, odds are they are correct.

Incidentally, cancer researchers aren't profiting off of human misery... they're profiting off of reducing human misery. Is there a better thing to profit off of? The ones you have to watch out for are the ones who wish to extend your misery for their own gains, but that's not required for profit, and in fact is often against their own long-term interests anyhow.