I'm not sure I understand your point so if I'm off base let me know.
Firstly, inheriting $200k - $1M doesn't keep anyone poor. It doesn't even stop wealth from concentrating at a level that harms others and warps society - it just prevents that level of wealth from passing down to people who did nothing.
Secondly, if everyone was poor who would be controlling them? You have to keep most people poor and a much smaller group of people unassailably wealthy to control them. That's exactly the problem that high death taxes address.