Big innovations like Bitcoin that change the world are always rare. If they happened everyday they wouldn't have been as exciting to watch them unravel. This is one of the reasons why we haven't seen any groundbreaking innovations in this scene.
There is also the problem of greed. Developers at some point started wanting to make money and only caring about profit, so they stopped taking the hard route of invention and started using the simple route of duplication and token creation to make quick and large amounts of money.