Exactly. People think that because we can have some completely unimaginative stuff with ideas from the 1980's that HTML5 is ready to be the future of browser gaming. And then when presented with the problem of complex physics, the solution is of course to add a special extension to browsers to handle physics. It's no wonder the browser is decades behind the desktop with myopic thinking like this.

You're right physics uses a lot of CPU, but I don't think games not using physics are automatically not worth playing. Did you see this platformer? http://news.ycombinator.com/item?id=3192719

I don't think presenting a retro platformer (which, FWIW, crawls here in FF 8) really argues your case much. Why should developers go back to making simpler games to get adequate HTML5 performance when they could develop directly for the target platform and use the hardware to its full potential?