The main issue is that "simplicity" is a very ambiguous thing. If your language is "simple", you need to write the same low-level code again and again every sin

The main issue is that "simplicity" is a very ambiguous thing. If your language is "simple", you need to write the same low-level code again and again every single time, making your own code NOT simple. Pushing all the complexity away from our program into the language means that our code is simple, which is much more important. Any improvement to the compiler is spread for free to every single program compiled by it. (I'm a go user, though)