Unfortunately, a large segment of Americans use far less of the available words on English,because they don't know them. English is a wonderful language,most of which has gone into decline from disuse.It did NOT used to be this way...even poor people knew more English than most in the middle class know today.*sigh*
Does anyone remember the PBS special "The Civil War"? In that special they read the letters of dozens of soldiers, North and South. Those "ignorant farm boys" wrote beautifully. Very few of us could match them.
It only seemed as if the middle class had a stronger vocabulary. They really didn't. In any event, a strong vocabulary no longer holds an appear for a middle class whose culture is now popular and largely visual.