Fair, but do we really need C levels of performance on the web? That's madness. They are mostly CRUD apps for God's sake. They don't have to be able to run liquid simulations at 200FPS.

IMO the level of Java / Erlang performance is, and should always be, plenty enough for the web.

For CRUD apps, JavaScript is plenty perf-wise already. The reason why there have been many attempts to push things further is precisely because people are trying to build web apps that need more (including 3D games even).