Governments essentially avoid this problem, and they have for generations, because they realized that names are intractably hard. This is why they give people numbers instead.
Here's my name written in my passport (US): "MC KENZIE PATRICK JOHNATHAN" The Passport Control Center is the only organization which thinks I have a space in my name.
If you go to Cook County and grab a copy of my birth certificate, it says "Patrick Jonathan McKenzie". I was a poor speller as a kid and thought Johnathan had two Hs until I was a teenager. Whoopsie. Now it does because it's just too much hassle to go get it changed now.
The Illinois DMV thinks I'm Patrick McKenzie. Ogaki City Hall thinks I'm McKenzie Patrick Johnathan in one part of the office, ミッケンジーパトリック in another part, パトリックミッケンジー in another, and ミッケンジーP in a fourth part. The national tax agency said, direct quote, "Sorry about our software being unable to accept your name. On the bright side, we really couldn't care less, as long as you pay your taxes on time."
Well, I know people who IRL insist on being called by made-up names, mostly goths, you know, something like Darkraven Bloodmisery.
I know a lot of people IRL who insist on being called by made-up names. I know Japanese and Chinese people who have "use names", because some white folks think Hideyuki is a mouthful and couldn't guess that he's a man. I know neighborhoods in Chicago where Irish Catholics are so thick on the ground that you'd better come up with a nickname if you're a Patrick or a Mary because otherwise half the class will have a hash collision with you. (I was Patrick Johnathan -- the other Patrick Jonathan beat me at rock paper scissors and claimed the coveted PJ.)
I also know some goths who use made up names, including a Robert who -- cheeky blighter -- insists he is really a Bob.
Also, just a self-preservation tip: don't ever repeat that comment near a liberal arts faculty if you value your sanity. They will be on you like vegetarian tigers/esses/etc on a fresh, juicy bit of fair trade tofu.
General caveats apply about edge cases (and Gender is specifically complex issue that maybe this advice is useless)
I have legally had a one-word name for decades. SS card. Driver license. On credit cards I fake a first initial, same with other DB-enslaved contexts.
Some time after the DHS was invented, SS changed their database systems. Where the SS used to list me as "myname," now I'm listed as "#unk myname."
Since my SS record no longer matched my driver license, when I went to renew my license I was refused, because the DHS tells the states that DL must match SS. That took weeks to sort out, but I did finally get my DL properly renewed, after they found the employee that knew how the DB system works.
Government IT.
Also, I know a fair number of people, who, for a variety of reasons, have their names in transition. These new names are not yet their official names, and they may change what they ultimately decide on. It's _really_ not the place of Google to effectively say "Make up your damn mind".
Well, there's a continuum of "made up", going all the way from Darkbane Bloodlovin' to our idealized gold standard of "Whatever two inexpert people who have known you for less than a few hours decided would be the best thing for the entire world to know you as for the rest of your life."
P.S. Got to love that I'm referred to as "patio11" in that comment. (I don't know where "My friend in middle school was from Puerto Rico and he just couldn't manage -ck most days so 'Patio' it was" fits on the continuum, but it stuck so hard that even my siblings routinely use it now, so I won't complain about it.)
Today I learned that I don't have a real name.
More seriously, though, most people I know IRL insist on not going by the name on their passport. If I had one, my name would be "Christopher", but I insist on "Chris" enough that I will not make my name "Christopher" on Google.
For a less silly example, though, most people I know whose names are not derived from their full legal names are some form of non-cisgendered people who simply don't identify with their given names. And, in the US at least, for most purposes it is simply not necessary to go the court-decreed route (we don't have a strict equivalence of a deed poll form for name changes as far as I know) and bringing court and public record into things can be unnecessary trouble until they fall out of those "most purposes".
Of course, these are only a couple of reasons why one might wish not to use their passport names online, but the main point is: it's rarely as simple as you think.
Because government has really one use for your name: the proper identification of a person for the purposes of the provision and execution of government responsibilities and services.
Google has a larger mandate, one where enforcing "official passport names" is not only inconvenient, but would also drive away adoption.
Not to mention, I have an English name, and a Chinese name. Only one of these appears on my passport, but depending on who I am interacting with I would very much like to (justifiably so) use my "unofficial" name. What is wrong with this? This is actually somewhat annoying for Facebook - I have relatively in Asia who don't speak English at all, and I'd like for them to be able to find me on FB... but there is only one canonical name on an account.
Google is developing a social system - a social system by the very nature of human identity cannot just have "passport names".
As I've said before, Facebook beat MySpace because it uses "real names". It's a lot easier to discover people you know, and that drives adoption. Google+ has to copy them, if they want to win the masses over.
They might be better off letting you have several, privately linked identities. For example, I could have friends under my "wisty" account, and friends under my real name. But they are best waiting until the muggles have already created great name accounts, and hooked up with their high-school semi-friends.
Once google is on near-equal terms with facebook, they can allow handles as well as real names. You could just move your "internet friends" circle over to your handle, and leave your "school friends" circle on your real name account. But until they have everyone's real name, this would be a poor business decision.
It's impolite to ask what their "real name" is. I've seen someone (call her X) get upset because someone pressed the point of finding out what X's mother used to call her (if that's a a "real name" in any meaningful sense). And it was pointless too, what could you do with that information?
There's lot's of inaccurate information there anyway, I have two "Jo"s in my friends list. On is male, one female. In both cases "Jo" is a contraction, in one case of a middle name. They also chose to be called "Jo".
I don't really see why Google+ needs to know or care. What people answer to is what people know to look for, so that's what should be shown.
Yes! Insofar as it can be made simple, that's how simple it is. I can't fucking believe how hard it is for some people (and databases) to accept that part.
I reminded of Catherina Fake, a Flickr co-founder.
if your point is "you don't actually know" then mine is "you don't need to even care".
Sometimes they are transliterations of each other, sometimes translations, and sometimes no relationship between them at all.
Here in Ireland we can translate our name in Irish and use that. I did that once for my passport. So I've had 2 different names on my passport without going to the deed poll, getting married, etc. all legally. What would be my 'real name' then?
(For the record the 2 string have a levenshtein distance of 10, so they are dissimmilar)