When WASM only give's a 10% increase in performance, is it really worth it ? While at the same time using "hardware" shaders gives 1000% increase in performance. If the goal of WASM is not performance, what is the reasoning behind it ? That you would be able to compile any!? program to be run in the browser !?

Not to forget wasm is in very early stage, once we get threading support(https://github.com/WebAssembly/threads) we can get much better results.