That's the old Ruby on Rails argument. In that specific case it only made sense when there were no similar frameworks for faster languages, but that's hardly the case today.

Not necessarily. For one, relating this doesn't remove the ability for incremental development. Another thing, there's very little actual innovation in software being done. Almost anything we use existed in some version in the past two or three decades, and it was much more faster, even if rougher at the corners. Just think how many of the startups and SaaS projects we see featured on HN week after week are just reimplementing a feature or a small piece of workflow from Excel or Photoshop as a standalone web app?