That's true for any political or philosophical system, but people still describe themselves as "Buddhist" or "socialist" or "stoic" or "antiestablisharian" or whatever.
For example, the philosophical stance of the Plane of Heaven (the D&D one, not the Christian one) EDIT: Celestia (Heaven is the Pathfinder version, got them confused) is one of adherence to hierarchies, where discipline and obedience are valued, and claims that those who are strong must serve and protect the weak. This is often referred to in game terms as "Lawful Good", and if you follow these ideals (even if you've never heard of Celestia or Lawful Good) then you are aligned with that philosophy—a philosophy that exists as a fundamental aspect of the D&D universe, one that is hard coded into the very laws of nature by the mere existence of the Plane that exemplifies that philosophy and the Deities who reside there.
It is a fundamental aspect of the D&D universe that there exists nine cosmic philosophies, and everyone within that universe is attuned to one of those philosophies—whether they are aware of them or not.
That is, in my opinion, the only way alignments actually make sense.