If such a constitution was written as you suggest, then it would have been outdated and torn up long ago. It would have been too rigid to stand the test of time. Also HN supports at least one emoji (囧).
There are several theories in designing constitutions. Many countries just give up and rely on common law instead. The more rigid constitutions tend to be ignored or the countries fall off into chaos, so America is somewhat successful in its implementation of constitutional law.
Chinese jiong should be the only emoji allowed on HN, since it is a valid Chinese character, but then so is a swastika (in both directions, non-nazi Buddhist meanings of course).