I don't really have an opinion about whether this is good or bad. I don't think it's a moral issue. And I didn't have any illusions about whether Google-Plus was or was not a public utility at the beginning. I can see why people who thought it was not a corporate-owned resource might be surprised. But you wouldn't have been if you factored that in from the outset.
There's a very simple business reason why Google cares if they have your real name. It means it's possible to cross-relate your account with your buying behavior with their partners, who might be banks, retailers, supermarkets, hospitals, airlines. To connect with your use of cell phones that might be running their mobile operating system. To provide identity in a commerce-ready way. And to give them information about what you do on the Internet, without obfuscation of pseudonyms.
PS: Unfortunately, most of the hoo-hah was on Google-Plus. I can't point to those articles because only people with Google-Plus accounts can read them, apparently. Remember folks, it's an invite-only system. It's not, in any way, a publishing platform, or the open web. So I'm taking screen shots of the main article, so everyone can read about it. (Update: Apparently it is possible to make posts on Google-Plus public. I was getting complaints when I linked to people's writing on GP from Twitter, from people who weren't able to read the posts.)