Two words:
Over complication.
Sure, if the point of the GLS had stayed as it was originally intended: have a username/password that every player needs to play online for easy GBLs. But no, we had to start getting funky with clan tags, clan invites, and all whatnot and crap. I want a clan tag of {}, but no, I need alphanumeric characters. I want to surround my clan tag with ANSI color codes, but no, that's not approved clan tags. Sure, you can try to cater to perfectionism, but the best system is no system.
Just leave it as a username and password.