[_bxg1]

That explains why they locked their platforms down, but it doesn't explain why they need to do that at the API level. They already totally control the storefronts and all software run on a console must be signed by them. That should be enough to prevent the Atari situation on its own.

[babuskov]

API lockdown is most probably to prevent crackers from learning enough about the system to create pirated copies of games.