I have written programs using native OpenGL/DirectX that are over a decade old. You are completely correct in that the technology is not new, in fact it is far inferior. However, the one thing to get excited over (and the only reason I even consider doing this type of development) is the accessibility of the finished product. It is far easier to get people to try out your product, game, whatever when all they have to do is visit a web page.

In addition, the "connected" nature of the web, real time communications aspect of it is exciting. Sure this could be done in C, but the cost of doing it in this type of environment is far less.

So while on a technical level it is not impressive, I wouldn't dismiss it.