Earlier quoted context omitted.
The only time it's not silly is when said dependencies are not just non-free, but covered under an NDA. If the API is under NDA then they can't release the code that uses the APIs. AIUI this is why FOSS games don't get ported to console, even though there might be people willing to fork up the money to pay for devkits and SDKs.
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.
I think that consoles shouldn't be locked down, but it's sensible granted the premise.