It's because Google+ was an attempt to appeal to the masses, not be a hackers cove. The benefit of real names is that people who know you offline can easily find you. They already know you by your given name and, because of Facebook and MySpace, they expect that to continue online. The products you can offer to people who know each other outside of the net differ vastly from the ones you can offer to people spread out among the country/world (With examples ranging from event planners to geo-tagging and facial recognition).
The subgroup of people who prefer pseudo-names is relatively small compared to the larger population. It seemed pretty clear that they'd become more lax after attracting enough users who didn't mind using their given names. I am surprised that they added another field for it, though. I figured they'd just stop enforcing the policy.
I use social networking in two countries, Taiwan and Germany, and less than half of my contacts use their "passport name" on FB. Almost none of my contacts are hackers.
In fact, only the hackers I know use their real names online because they're freelancers and build a presence. I wonder if that leads to the assumption among hackers that only weirdos would ever need this feature. Stating that only n% of n% of n% would ever need privacy actually sounds even more insulting than just calling us "weirdos".
apart from facebook (which cleverly leveraged existing relationships to create a culture where 'real' names were expected) virtually every single internet community is comprised of people operating under pseudonyms. i'd say the subgroup of people who prefer pseudo-names is the larger population.
Facebook is the model they had in mind when building Google+. The default circles were “Friends”, “Family”, “Acquaintances”, “Following”. The main method of recommendation was through your most contacted gmail contacts, a private form of communication. Discovery isn't structured like a forum, sorted by topics of interest. Instead, posts are limited in scope by circles, and organized by poster. (There is the stream, but that's built from people you've personally added)
They wanted a product that took your social life online. To that end, they tried to attract those kinds of people. The majority of sites with pseudonyms are open forums or comment boards. Most of the people you meet there you've never met offline. You can't offer people like that photo-tagging software or groups to set up real-life meets.
To chadmalik and gurkendoktor: Both of you are right. There are justifications for concern over privacy and I think Google went too far in enforcing its policy.
