There is no excuse for NOT being able to use a mobile phone without registering to some kind of service. Actually, forcing users to do so or even make them believe that you can't use your phone without such account should be illegal.

I do have a Nokia account, because I (naively, undoubtedly) believe Nokia gets little information from it, as I use it solely for the store. iOS, Android and I guess Windows Phone as well are way too invasive. I will not buy any of those devices.