No, it could be the reason. The patent/money issue is related to the initial FDA approval, which is very expensive (clinical trials). If no one foots the bill

No, it could be the reason. The patent/money issue is related to the initial FDA approval, which is very expensive (clinical trials). If no one foots the bill for the testing, it won't spawn a FDA approved thing, right? And if it's not patentable, then it's not worth the effort to go through those hoops, because you won't be able to recoup the costs of doing the FDA approval steps because others could also bring generic versions to market right away, without a cool-down period, and at the same price. If it is patentable, then it's worth it to make the drug and get it approved. You'll have 20 years to recoup the costs before generics can appear.