There's probably a word that the parent was looking for; it wasn't quite aesthetics, at least as you've defined it.

Sometimes you can write code that looks "prettier", at the expensive of the ability to read and reason about it. Optional braces are frequently used for this effect. Yes, optional braces allow you to fit more code on the screen with less noise—and therefore could be thought to enhance some kind of readability. But at the same time, they require you to think harder about the grouping of the code around them. Unless you've got a reformatting linter, you could have code like this:

    if(foo)
      bar; baz;
    quux;

and optional braces require an extra subroutine to be constantly running in your head, looking for those mis-arranged `baz`es that will get executed anyway. That cognitive load detracts from your ability to read and reason about the code.

(What'd be really interesting, in my opinion, would be to make C's braceless blocks, and only braceless blocks, have semantic-whitespace. Then the above would be able to be easily reasoned through: `baz` is part of the conditional, because it's on the same line. But this breaks a lot of rather old and inflexible assumptions about how C is parsed, that macro-writers et al depend on.)