See, the idea of a singular real name is interesting to me - I have a small handful of names I'd consider "real". It's the same with a fair few people I know, to varying extents, due to the groups I'm involved in.

The ability to use many names is strongly tied to the ability to identify yourself. Being forced to use a single name in all contexts, whether you want to or not, is relinquishing that ability - it's being told who you are permitted to be by an external force.