As a german I can tell from experience that in Germany it is much more accepted — and quite often even sympathized with — not to have a facebook account than for example in Spain or Brazil. And it makes me proud, if I’m allowed to add that.
In fact, I do have a device people call a mobile phone, however, I don't use the cellular network. I don't even have a sim card. It's virtually a PDA.
The reason for me to not use the cellular network is threefold. First, I like how one spends more time with the immediate vicinity if there is no way to digitally reach out. Second, I disagree with the widespread collection and storage of connection and location data. I feel nobody has the right to make a social graph of me or track my location. Third, and most important, I want sovereignty about the machines I own. That requires a level of openness in hardware and software which available mobile phones don't have.