But that's not really the worry. It's always been possible to obfuscate JavaScript. All that changes with WebAssembly is that it might drive even more needless code, and complicate the web's architecture even further.

For example, web browsers for the blind become far harder to implement when ordinary websites are using heaps of boated JavaScript. (The web used to have HTML for content, and CSS for presentation. No longer. Now it's just a mess.) The problem would be compounded if WebAssembly+canvas were to catch on.