To be fair, you can generate asm.js with quite readable names (use -g in emscripten for example). asm.js does not require that you also minify variable and func

To be fair, you can generate asm.js with quite readable names (use -g in emscripten for example). asm.js does not require that you also minify variable and function names (and whitespace), that is orthogonal, and done on all JS these days anyhow. If you do not minify the output, then asm.js's readability is somewhere in between x86 and C. It's far easier to understand than x86, but it is still definitely less readable than handwritten C because it's machine-generated and optimized.