This made me wonder, if you got a recent Mac (with recovery partition), and after, say, 3 years or whatever, and you've long upgraded to the newest OS. Now you want to sell the Mac.
How do you return the Mac to the OS it originally comes with? (If you don't, you would a) have to login with your Apple ID to install the OS (bad idea), or b) sell the Mac as "with no OS" and the other party would need to buy the *same OS that the recovery partition is based off* off the App Store *on another Mac* before being able to use it (oh, it's old and no longer being sold? You're SOL, it seems?), or install another OS entirely (Windows or what you).).
Doesn't sound right to me...