> But that’s not how humans writing code generally think about ambiguous expressions. You can see that by how few precedence rules programmers tend to internalize

I'd argue that it is how humans think about ambiguous syntax, except in the special case of operator precedence, which is the most complex example. A more salient example to me would be, say, the case of an ‘else’ block after a double-‘if’:

  if (c) if (d) X; else Y;

It's technically ambiguous, but you only need to run into it once, see how your IDE auto-formatter indents it, and then you've internalized the precedence rule immediately.