Historical Reasons

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.

> You can’t wear 99 in the NHL now, or 6 in the NBA. Maybe you shouldn’t be able to log in as dmr for the same reasons

I can't tell if this is a serious argument or just relying heavily on the use of "maybe" to get away with expressing something that they know most people will disagree with, but I feel like it's a huge stretch to imply that what makes sense for numbers on maybe a couple hundred professional athletes' shirts when they're playing publicly on televised events would apply at all to usernames for millions of normal on their own private devices. To just call out one of the many obvious concerns: this would presumably break any existing logins (and scripts referencing the home directory). The MLB even took this into consideration when they retired 42 for the entire league in honor of Jackie Robinson; any players currently using the number were allowed to continue using it until they retired, and that's was just out of courtesy rather than any actual necessity.

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.

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I also think that, as important as Unix was for the history of computing, it's also outdated in a lot of ways that I think are holding back computing.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.

I suspect that coming up with a set of rules as to who would and wouldn't be honored in such a manner would inevitably lead to some real-world violence at some point in the future.

Let's leave this out of our commonly used code.

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

I was always a little upset, a decade or so after I left amzn, to have some 3rd party interaction with a sysadmin there, who upon being told that I had uid=1 informed my correspondent that there was no uid of 1 on their systems anymore.

I mean, locking the account was entirely understandable. Deleting it, though ...