Comment 7 for bug 488158

Actually, now that I think of it, we can't avoid forcing the UID because we implement user profiles in users-admin. Those allow the distribution/admin to present users with typical account types, which set sensible default values for home dir, shell, groups membership (esp. admin), and UID.

It's kind of silly we implement this on the GUI side, but as we can't be sure the distribution supports this kind of feature (and none does ATM), moving this responsibility to adduser would require modifying deeply the protocol, and add fallback support for systems that don't support this. So it's not going to happen soon, given that adduser would have to support that first. Administrators using users-admin should ensure the profiles are correctly defined, or not use the tool at all. All I can do for now is have a look at the profiles handling code so that when no profiles are set, we don't specify any UID, and the backends leave adduser decide for us. Not very hard, but our protocol does not support it ATM.