Stop crying, everyone.
It's a twelve digit number, that only needs to be entered once, since we've pretty much moved on from the "separate FC for every game" disaster.
It still sucks and would be better off with a username, but at least it's all tied together with one code per system/account. Would we really want a bunch of randoms adding us just because they know the username you use? I don't.
How many people have ever added you out of the blue from an online game?
Between years of Xbox 360 usage, I can safely say... probably one or two. "Randoms" don't add you randomly. People usually add you to your friends list because you kick it off somehow. Like if you both find yourself having a good time playing CoD you may add each other to continue having a fun time at CoD.
I don't want to redeem a code every time I want to add someone. If you literally just produce a console and it's already got a significant detractor, then how the fuck is this next gen.