Unfortunately they are going against the famously unethical and privacy-eroding facebook, which has a real-names policy and the bans to show for it (also, NSA alumni on the board). And besides “the competitor already does it”, here is what Google's reasoning may be:

Requiring your real name makes it easier for people you know in real life to find you.

Interactions with people who know you in real life will keep pulling you back in, because these people are harder for you to ignore.

Once you give your real name and the rest of your identity (they have been badgering for phone numbers for a while, to keep your youtube account, or open a google account, or to avoid annoying security/recovery notices when logging to gmail), you won't be asking yourself “should I be sharing this” questions, because you'll be in the habit of trusting them. Other features, like payments, deliveries and phone notifications, won't have to nag you for explicit personal info anymore.

So I think they will offer temporary or per-circle identities at most, while people who want privacy from Google or the US and affiliates will have to fake it while it remains possible, or be shown the door.