I'm not sure the Alexa and F35 were panicked responses to the Red... the Arri D20 and Panavision Genesis predated the Red, and are very clearly the ancestors of the Alexa and F35 respectively - they use the same resolutions, sensor layouts and colourspaces, if not the exact same chips and recording formats. Not to mention the Dalsa Origin, a 4k camera out well before the Reds.