You're right that the past was not 'move innovative', but I think it's misguided to think we are not discovering new things every day - we certainly are. They're just not noticed immediately because of relative 'obscurity' to an existing paradigm we have built around imperative and structured models of computing. This is the real difference between the past and now - in the past they were free to explore without restraint, but now we are carrying baggage that can't simply be dropped (The requirement to remain compatible with C, JS or whatnot, and worse, the unwillingness of many programmers to learn new things.)
Even C had baggage, from (B)CPL and Algol. C wasn't some magical innovation that appeared, but the result of incremental improvements to an existing paradigm, and the popularity of C++, Java and the likes happen for the same reason.
Conversely, LISP was hugely innovative because it introduced a new paradigm for thought and experiment, which led to even more new ideas appearing that wouldn't have been discovered if we were only stuck in an imperative world, but some of those ideas were then able to be brought back into the imperative world which brings about more innovations. Likewise, integrating procedural ideas into the mathematical world has brought about new innovations too.
I don't see languages like Dart as very innovative because they barely add anything new to the mindset. It's largely existing ideas that have been tried before, getting rid of some of the bad ideas of past, and putting it together in a neat package, however, it's still very much in the same existing paradigm, and incremental improvements to an existing paradigm only tend to solve small problems.
Bigger problems will be solved by completely new ways of thinking, but one needs to be able to abandon existing frameworks in order to explore them, then worry later about how to integrate the good ideas into existing models. This can be seen with LINQ - an innovation which cleverly linked ideas from FP into C#, but which no imperative-only programmer could've ever imagined within their limited paradigm.
I think people are so disappointed with Dart, and somewhat Go, is because there's a huge amount of innovation in programming languages outside the popular paradigms which they have largely ignored for the sake of making 'simple' languages to appeal to popularity, but many hackers are more concerned with discovery, and advancing our subject.