[Symmetry]

So higher profits WILL result in more money being removed and not invested in R&D. If the companies weren't doing this they wouldn't be living up to their responsibilities as corporations.

That's true at some level, but not in general. Remember that the people who invested the money that paid for the research that caused the drugs to be developed could very well have just sat on their money and not invested it in the first place. Those capitalists had a choice as to how much money to invest in drug discovery, and since they're greedy capitalists they invested the amount of money that they thought would make them the most money. There's a diminishing returns thing going on where there are a whole bunch of possible research avenues open, so the more money they put in the lower percentage return they get. When the percentage return drops below what they could get from other investments, they put money in those investments instead.

To the extent that drugs start to have higher profits then the greedy executives will see that they can make even more money by investing more money in drug research, possibly much more than the increased profits but also possibly much less. It all depends on how fast the investors think that the diminishing returns on investment kick in.