Jeez, I knew people would comment on this. I put it in quotes because I don't mean turing complete it in the technical sense, but as an analogy. It is "fully functional", you can achive basically any result that you can with Flash. Analogous to the fact that a Turing complete system can simulate any Turing machine, I mean a certain interactive graphical programming environment - like HTML5+js for example - can remake any Flash game.

But that "Turing completeness" or "result achiveability" is not at all the interesing point.

The point is that despite this "completeness" or "equivalency" there is a difference. You could write a line of business application in plain C or say even FORTH, but it is probably easier and makes more sense in C# or Java. And you can create great games and animations in HTML+JS, but something was lost in the experience, and in the tooling, that was available with Flash.