Perhaps the real single point of failure is identifying as anything. I might identify as a rationalist when speaking to others, but in my own mind I think such an identification would be unhelpful (and could be harmful).

Deeper, more controversial answer: The single point of failure is words, or rather the fact that social convenience strongly impels us to make a medium designed for communication double as a medium for our own thoughts. The phenomenon of self-identifying as an "X-ist" (even if initially only for social convenience) is just one of the unfortunate consequences.