Do development costs really need to be recovered through sales? I thought most of this research was done on federal grants.
The financing model is problematic. Return on investment is much higher and faster in IT, besides there is a mismatch between what the market favours and where future clinical needs are (the antibiotic crisis, neglected tropical diseases).
I'm not opposed to the idea, but I think you'd struggle to make it politically achievable.
And if not, why not? There may be folks who think public research grants shouldn't exist, but since they do, what else would be worthy of such support if not public health research?