You are holding up code as an example of clarity and scrutability, and because it is mostly restricted to ASCII? Hex code is even simpler - only 16 characters.
> where a mathematician writes "Σ", a programmer simply writes "sum".
Communities develop shorthand and terms of art for things they write a lot. Mathematicians need to write lots of sums; programmers have their own shorthand and terminology.
Hex code doesn't allow you to write words. And "sum" is simply better than "Σ". There is no way to know in advance what the latter means, while for the former understanding of verbal English is enough. Mathematicians basically use an iconographic writing system like Chinese.
> where a mathematician writes "Σ", a programmer simply writes "sum".
Communities develop shorthand and terms of art for things they write a lot. Mathematicians need to write lots of sums; programmers have their own shorthand and terminology.