That limit is the length of a patent (plus/minus some factors like extensions and time to market). That's been the deal ever since the FDA was a thing. It's nothing new.
My understanding is that the controversy is over a newer type of fast acting insulin that's not yet generic. In general insulin is really cheap, but the really nice new stuff makes life a lot easier for diabetics so everyone wants it.
Turns out many many of the drug companies have been abusing the systems. The feds created a process for handling drug patents, and companies keep filing extenuating patents on existing stuff, and they also have been submitting not just drugs but devices to the registry illegally too, to hold monopoly. No one has guarded the registry.
FTC is finally taking some charge, after all the other agencies (patent office, FDA) have failed to do any enforcement.
My understanding is that the controversy is over a newer type of fast acting insulin that's not yet generic. In general insulin is really cheap, but the really nice new stuff makes life a lot easier for diabetics so everyone wants it.