What secret sauce APIs are there to protect on the consoles? I guess the DRM side they might want to keep as secret as possible, but everything else strikes me as boring standard stuff. Here is how you draw a triangle, register an achievement, pop up the console store, whatever.
Who knows what some enterprising hacker might be able to glean about the workings of the console by looking at the APIs.
I think that consoles shouldn't be locked down, but it's sensible granted the premise.