Really the underlying problem here is that "Google+, the unified platform/identity system" has the same name as "Google+, the social network which lives at plus.google.com". People just blank out anything they do/say due to the assumptions which arise from conflating the two.
Let's say I have an anonymous pseudonym used on a number of other sites. I can now have it on Google+, with one big difference: it's no longer anonymous. Google will know who's using it because of their real name policy, and can then put two and two together across sites they don't own.
Anonymity means no-one knows who you are, not "no-one except Google."
You don't need a G+ Profile on your @gmail address to create G+ Page pseudonyms for Youtube. Your main address will continue to go plus-less, and other services which strictly require a Real Name/G+ profile (like Places/Play reviews) will continue to nag you to create one.
... I did not know that. Obviously, from my post above. Yay, I have a Plus page with a nickname! So, can I comment as Pxtl? Can I do that on Android play store reviews?
Even made a video explaining how to do it: http://www.youtube.com/watch?v=jKBGsu0TxnY
Really the underlying problem here is that "Google+, the unified platform/identity system" has the same name as "Google+, the social network which lives at plus.google.com". People just blank out anything they do/say due to the assumptions which arise from conflating the two.