I don't think an apology in an overreaction given that this prank is driving away at least one
valuable member of the site.
This thread is enlightening to the big issue. People are quite divided over the issue, and many people were offended. While some are trying to argue as to whether they should, I think that is kind of missing the point. This is the biggest day of the year for this site, and one that should be fun and lighthearted, not one that leaves us discussing Nazi Germany. There are plenty of ideas we could have done instead that don't leave people getting upset, angry, or leaving the site over.
The idea of everyone having the same forum name could have been done 4chan style with anonymous, and complete with usage of overtired memes. Or a TASing race could have been done Borg style. I don't know. My point is that there was no need to be this offensive. In hindsight I feel like this was bad taste, and I apologize too, on the behalf of the site.