Mdd
Good question.
Maybe because every Yid has tremendous potential. Maybe because every Yid has unlimited siyata d shmaya waiting for him. Maybe because really there is no such thing as a “regular” Yid.
If so, then what did the Ramchal mean?
I don’t know. Maybe he meant anyone who hasn’t yet been inspired to achieve Shlaymus. Or who feels it’s just not for him. But there is no doubt that every Yid can achieve greatness.
It’s a question for much bigger heads than mine.