The issue at the start of the conversation is not about speaking or gesturing. It is about using the Latin alphabet properly (i.e. phonetically, as it was designed) or "with some imagination" as the English does.
The alphabet is used to communicate the spoken words. Not the concepts or something else, literally the spoken words. Is a big part of why slang is so popular in fiction settings, as they would use the letter to convey pronunciation. Because the letters generally represent phonemes.
