Because of the previous culture and history of the people. When the culture and history are different, there is (almost) socialism in countries like the Scandinavian ones, even without officially they call it and want to build it consciously. It just happens when the certain people have got the right culture, conscious, habits... Now notice something important: when a country has not enough democratic history and democracy culture, the result (totalitarianism, dictatorship, etc is the same: for example Russia killed the communism, started to build capitalism and ended up as a dictatorship (neu-feudal type, like China now)...