I could agree with giving sysadmins a way to specify a list of disallowed usernames (which would be useful for more reasons than to retire certain usernames, e.g. many sites would probably disallow "admin" as a username, and depending on maturity of the userbase might also find it valuable to forbid profanity as usernames). But it should be in a text file somewhere in /etc, not hardcoded into the source of useradd.c: different sites would have different requirements, and David M. Robertson (a fictional person I just made up, and if that happens to be your actual name then congratulations), who works at a small startup whose standard practice is three-initial usernames, should not be forbidden from using the username dmr just because someone famous also had those initials.

I respect Dennis Ritchie's accomplishments too, but that doesn't mean I want to encode his username as a retired unix username, and in free software projects it's possible for anyone in principle to remove that line of code and rebuild the OS.

I also think that, as important as Unix was for the history of computing, it's also outdated in a lot of ways that I think are holding back computing. We should be reconsidering the use of C to write an operating system at all, as well as the concept of a username in the traditional Unix sense. My ideal operating system wouldn't have `useradd.c` as a concept to begin with.

mandatory mention: It is tradition to refer to this argument as 'for hysterical raisins', when something kept being done in a certain way, only because of some initial irrational arbitrary choice, is mandated with this argument.

Cute idea but I disagree, I don’t think it would be too viable