To people who are confused about why have a new Xbox S and Scorpio you just have to look at the phone market.
Scorpio is the new Flagship Xbox, like a flagship Iphone, it is the top dog.
Then they have a older reduced price for cheaper tech. in revisions. Xbox S is for people at a lower price point. Think teenagers who are getting their first console at xmas, people in non-western markets who get PS3 and Xbox 360s years after everyone else.
People buy Iphone SE's because they want a Iphone experience but they don't want best of the best.
They do it this way so Xbox remains a shared Ecosystem where the games work on all xboxs and where everyone can play together regardless of what xbox you have. It examplifies that Xbox is a delivery system, not just a static analog box that cannot grow.