I know exactly what you mean and her/his posts don't seem to point in this direction no matter how many were written or how many times I re-read them.
How can SE stop this from happening without taking away current rights? So if I payed for 4 accounts I can't let just one character kill everything my own leve party? I would have to play each one at the same time? If I use my wife account for the extra leves will I be banned for doing so?
This topic is mediocre and affects only those that choose to make it more than what it is.
edit: The above is not something I have ever done or plan on ever doing(my wife also doesn't play). I just choose to be empathetic on topics and I just don't see why anyone cares so much about this(no matter how hard I am honestly trying). It's just being way too nosy by wanting to hover over someone's shoulder and judging how they choose to play.