I think it's a fantastic talk, and that Bret Victor and Alan Kay are geniuses. But I feel that they both promote the idea that we definitively solved all these important computing problems years ago, and that people are just too clueless/resistant to catch on. Yes, I agree that many good ideas have been culturally "forgotten". But for the most part, the reason these great past ideas are not in use is because nobody has made them into a compelling product.
Their attitude is comparable to someone saying "oh I invented the WWW in 1985 but nobody would listen to me", or "oh I invented Twitter before Twitter but users weren't enlightened enough to appreciate it". Almost all good ideas were already had before, but they are worth comparatively little, and unlikely to catch on, until they are reified into something that people want to use.
I agree with them that probably more people should be working in certain areas (e.g. new ways of programming). But if they really had it all figured out, then why haven't they themselves made the amazing new programming language that we all use? What if it's the case that some of their ideas are good in theory, but are hard to translate into a usable product? Most people accept that execution>>idea in the world of startups, but don't acknowledge that the same may apply here.