Yes. But it is not reasonable to expect every (legal) service to be offered in every legal/regulatory environment.

This is not to say that Facebook will not or should not offer its services in Europe. Simply that there are possible legal environments where Facebook would be legally allowed to offer its services, but where it would be economically unsustainable for it to do so... and that it is often quite difficult to understand these sorts of effects ahead of time.

Edit: clarification