The registration page
does do some validation, but all it can do, really, is validate the "two names" part. It can't check for nonsense names, or celebrity names, etc. If have some code that can do this, I'd love to have a look!
I have no idea what "we're all programmers" means. "Programmers" are a very diverse bunch, including people from all over the globe, of several genders, and of all ages. One of the reasons for the naming policy is to try to put them on the same footing. While some people might be impressed by "javabunny673" or "Harry Johnson", other people will be put off. We find that using real names helps people act in a polite, civil, and respectful manner.
But all this has been discussed before; there's nothing new under the sun.
Here is the canonical
thread for discussing the naming policy; feel free to add to it.
[ September 02, 2006: Message edited by: Ernest Friedman-Hill ]