Why make a console? To own the living room. There is enough money to be made from consoles.
2nd, why should Apple become a game publisher on the Appstore as well? Because they currently only take 30% of revenue and not 100%.
but game development is a huge risk - a few years back it was said that 3 of 10 big game projects actually make money and have to make up for the failed ones, but right now this quota might be better because publishers have become way more risk averse and are actually not doing much besides their hit-franchises
just taking 30% of any game release on your platform on the other hand is 0 risk and you get to profit from other people's success (as long as your platform is too big to ignore)