Supporting the LaTeX expansion is just a necessary feature of any Julia-compatible code editor. It is not then particularly more difficult to type `\sigma` over `sigma`.
Also note that other languages often support non-ASCII identifiers as well --- for example, `σ` is a completely valid identifier name in Python (though it is more restrictive than Julia, `σ²` is not valid in Python and yet is valid in Julia). It even works in C, but that might just be a GNU extension.
Also note that other languages often support non-ASCII identifiers as well --- for example, `σ` is a completely valid identifier name in Python (though it is more restrictive than Julia, `σ²` is not valid in Python and yet is valid in Julia). It even works in C, but that might just be a GNU extension.