Yes, I agree with you that the way we manage our contact date is outdated.

The problems nowadays are:

1) If you include pseudonyms and literally all user data, you will earn the distrust of millions of users that don't want this data centralized in the databases of one company.
(I know it is possible to figure out almost all the interconnections e.g. via IP, Cookies, Location data, your browsing history. But still they are given implicit. Handing all your user data to one company firsthand plays in a totally different league.)

2) This system, especially the automatic updates via sent out API calls, requires deep integration in countless pieces of software. Windows, Mac, Linux and all their ways of managing contacts, the corresponding mobile systems need to adapt and what about the business sector?
You could counter that it is a standalone app and the user has the choice on every platform. And that would be the next problem. All the existing services (about.me, dooid.me, even the Gravatar, or even providing a downloadable or scannable .vcard file or QR-code on a self-hosted webpage) are not used by any majority of people. Why? – The majority simply does not submerge that deeply into the technology.
Yet another service that bring yet more responsibilities (setting up privacy boundaries etc.) might be appealing to the techy-nerdy kind, but not at all to "Joe Average".

3) What this would need is huge company's backup. And to be honest, Google has had the chance...but they screwed it up. Google+. The idea behind the circles is great (hence the resemblance to your "spheres"?). But tying it to yet another social network and forcing it upon it's users is not the way to build a user base that trusts and accepts the platform.
I don't believe any piece of statistic released talking of 400 Million registered users (of course, because they force it upon the Google Play and YouTube users) or the 100 Million active users (of course, YouTube commenters, still want to comment). If I check my Google+ Stream it is dead to 95% of my contacts. There is less going on than on facebook. (Which we all apparently distrust and has seriously lost the contact management game.)

All this leads me to the conclusion that the introduction of an important functionality like the one you describes can't be done by any kind of service.

It should become a "protocol". Maybe a vcard-protocol. And in the best case a P2P based one that is encrypted. Why?
- My user data doesn't change every second, so there is absolutely no need for 99,99% availability.
- Our smartphones are online almost 24/7 anyways. And in addition our various other internet access devices even increase that number ;)
- Ot the information could be circled around in the P2P-network, highly encrypted. As the data size of maybe a profile picture and a bunch of contact details is not really an issue, this actually would be feasible.
- It could be combined with PGP, maybe even use the very same keys. Which could and should increase the number of users encrypting their conversations.
- The information would not leave the users hands unencrypted.
- The possibilities are defined by the protocol and the user has to set up allowances (sphere permissions) accordingly on the platform he uses.
- As you now can setup various IMAP mail accounts you could create various vcard-information snippets for all the various identities you want to manage.
- A unique ID of course is necessary, this could be used for the NFC/BT or just motion-sensor/timestamp/location based ("bumping") handshake to exchange the information. The encrypted vcard-information package can of course be published directly or in form of a link/QR-code via NFC/BT/local Wifi.
- It should not be file based to the user.
- The encryption (I don't know if PGP allows this) should be able to terminate itself if the user didn't refresh the permission or didn't prolong the availability.

The big problem is...how can a protocol like this be made attractive to be used.
One would need a group of manufacturers/companies, like Google with Android and it's web-based contact database and Apple with iOS and it's horrible contacts App.

The problem is...there is too much money in user-data...
So I guess all of the above will remain a dream. *sigh