- Longer names mean longer lines, and lines that are longer than your viewport are terrible. Less of a problem with modern ultrawide screens, but passed ~100 characters, it starts becoming a problem in some cases (ex: diffing). Personally, I have a soft limit at 80, hard limit at 120, because that's what works best for me.
- With such rules, variable length is a hint of its scope. For example, I tend to use "i" when the loop body is small, "idx" or "index" when it is a bit larger, and a more descriptive name when it exceeds one screen. This way, just by looking at a single line, I already have a hint about its context.
- Just because a variable name is short doesn't mean it is meaningless. For example "i", "j", "k", are loop indices, "x", "y", "z" are point coordinates and "dx", "dy", and "dz" are differences, "a" and "b" are both sides of a comparison function, "t" can be a temporary variable or a time depending on context, etc... The corollary is to make sure you use your single letter variables consistently. If I see an "x" in a place where a coordinate can be used and it does not refer to a coordinate, or an "i" that is not a loop index, I will be confused.
