Are you arguing that the sound of "J" in English (and the very different sounds of it in Portuguese, Spanish, Italian etc.) is wrong? Sounds of words change over time and that's probably why the same letters are pronounced so differently in different languages, though they might have been used to represent the same sounds originally.
Not arguing that, these langugaes just use the alphabet differently. I was mainly reacting to the "speakers of every other language that uses the Latin alphabet" part to give some counterexamples.
