At first there may seem some good arguments for saying people should put their name next to a review. But even if I'm not bothered by using my real name, a problem is that it means linking Google+ with the account on your phone. Many people, myself included, use a special Google account just for our Android phones, to reduce the risk of information sharing or snooping - but now to leave a review, we'd have to link it to our real names. What if Google start to apply this policy gradually to other services? Not only does this mean more services requiring a real name, but it also means users having to link up Google accounts that they had previously kept separate (since you're also supposed to only have one Google+ account).
As a developer, I know it's annoying to get the occasional bad review or rating for seemingly dumb reasons, but I'm not convinced a real name policy would prevent this - such reviews are sincere even if misguided, not malicious, and it's perfectly someone's right to give a 1 star review, so why would they be more deterred than anyone else? It's already possible to flag spam reviews. On the flip side, it's pleasing to get good reviews, and it would sadden me if people are deterred from doing so, due to the Google+ policy.
Reasons for wanting to use a pseudonym might be users of an app for say, a gay or BDSM website, who want to give feedback. There isn't just the idea of avoiding real names, but also that people who use a pseudonym on a website, that pseudonym would be their "common name" for that app. An actual case involved a Second Life user who signed up with their SL username - it would surely be better that they leave a review of SL apps with their SL username. The mistake by Google is assuming people have one "common name", when people typically have different pseudonyms in different circles - ironically using a "real name" can end up being less identifiable in some cirlces! Others may simply be deterred from leaving reviews because they can't be bothered to sign up to another service.
It doesn't help that Google's enforcement of "real names" on Google+ has been appalling - whilst claiming they only mean someone's commonly used, not necessary legal, name, in practice people have been required to use only their legal name even where they have an alternative common name, as well as having problems because their legal names were unusual. ( http://gawker.com/5824622/names-banned-by-google-plus , http://infotrope.net/2011/07/22/ive-been-suspended-from-google-plus/ , http://en.wikipedia.org/wiki/Nymwars )
This also smacks of "let's desperately try to force people to use our failing social network" - moves like this make me less want to (as someone depressed by Facebook, I was looking forward to a Google alternative that might have a chance of challenging Facebook).
It's no great loss - I and others simply won't leave ratings. But as an Android user and developer, I think that isn't a good thing.
(It also seems odd that I can publish an application without publishing my real name, but I need to publish my real name just to leave a rating...)
Google has a bad history of finding ways to force people to use one of their services.