I interpreted slowpoke to be arguing that the single identity theory was oversimplistic and illusory, a position with which I agree.

anigbrowl then came in with his "Skkkkrrrrriiiiittttcccchhh No, most of us are pretty happy with it because it works" remarks, which I felt was rather flippant. My response was meant to show anigbrowl the logical conclusion of his position. It's not an unrealistic possibility either, I believe it's been at times the official policy of Facebook, Google Plus, Blizzard, and S. Korea.

My point is that, no, a single identity doesn't work and really it never did. We all use many different context-dependent identities as we interact in life.

All you really pointed out is that his legal name is not "anigbrowl." And all he argued that was legal names do have some special importance, and it's out of touch with societal norms to say they don't. The fact that his name isn't "anigbrowl" is irrelevant to the fact that legal names have some special importance — both of these facts can coexist at once.

The logical conclusion of anigbrowl's position is not "You will be permabanned from this service if you can't produce a driver license reading 'anigbrowl'." This is an argument against a much more ridiculous stance than the one he took.