The problem with that approach is it inhibits a lot of perfectly-sensible optimizations. If you force the compiler to leave it up to the machine, you force it t

The problem with that approach is it inhibits a lot of perfectly-sensible optimizations. If you force the compiler to leave it up to the machine, you force it to preserve the same stack layout, the same memory write, and the same execution order relative to everything else. You basically forbid it from working with an execution model at any level higher than "a giant array of bytes," because now you have to preserve the naive behavior of that giant array of bytes. But this is not really useful for correct programs. The committee's intent may have (accidentally, indirectly) been to codify compilers that do very little optimization, but that doesn't mean it was a good idea.