My late husband, A US Air Force officer explained to me the letter-explanation-words were chosen because they are know and/or understood in most of the world's languages.

My understanding was that these particular words were chosen to have as little overlap as can be contrived, so that if part of the word were garbled by transmission the correct letter could still be determined accurately. (As opposed to the "standard" letter names, in which it can be hard to differentiate among b/c/d/e/g/p/t/v/z or a/j/k or m/n or f/s and such like if there is any fuzziness to the reception)