they just want people to use their real names so that people don't act like fucking idiots
Twitter has shown that you can run a successful service without demanding real names.
I think a huge mistake for G+ was that they didn't make it clear up front that the real name policy was going to be enforced. It wasn't even clear to me that policy existed up front. It looked like they got greedy when they saw the early popularity and decided to take advantage of it by changing the rules. It ruined a huge part of G+'s selling point. They came out of the gate saying "We have better privacy than FB". Everyone cheered. Then Google said "But for reasons we won't explain very well and which were never stated up front we are now making everyone who uses it tell us their real names". All the privacy advocates who were cheering stopped and started booing. Dumb move Google, dumb, dumb dumb.
Even if they did announce the real name policy up front it still is a huge issue because that does not exist the rest of Google services. That means a large number of people who happily go by any moniker they like on Google services, GMail, etc. suddenly find they can't use Google+. They either have to expose their real name on an account that has years of history that they might wish to remain disconnected from their real name or they have to make a separate account for G+. Google wants its cake (people using real names) and to eat it too (connect G+ to everyone's existing Google services). Unfortunately for Google these things conflict.
Google seems to be making an art form of screwing up this kind of thing.