That is the point. A legal time limited monopoly. But it has to be time limited or progress is stalled. Five years is plenty of lead time to be remain ahead of competition.
agreed. i often consider that "open source" IS exactly what you are saying: release to others a non latest version of software, in continually rolling fashion, whereas upstream is internally used.
This seems to hurt society more than it helps. Plus now we are forced to hear yammering about chinese competition "stealing" (translation: competing).