Obviously, not all of us are certain that this was "the right thing."
Fortunately, that's not my problem.
It is, however, the subject of a discussion in which you've opted to participate.
The subject is "Pedophilia and the Non discrimination policy". I've opted to participate to dispel the notion, suggested by you, that a perfectly productive editor was blocked simply because the editor happened to be a pedophile. This is a hypothetical which I don't believe will ever arise in reality, and certainly not often enough that there is a harm in simply blocking pedophiles on sight.
Jesse mentioned "the idea that paedophiles are inherently evil and can do no good". I'm not saying that, but I do find the idea that someone who openly admits to being a pedophile (*) could also be a good encyclopedia editor, to be a bit far-fetched.
(*) Which implies that they don't think there's anything wrong with being a pedophile.
I don't expect to convince anyone of this. In fact, I suspect a number of Wikipedians on this very mailing list would take the pedophiles side on the issue of whether or not there's "anything wrong with that".
Yes, and the same applies to murderers, rapists and neo-Nazis in our midst. This is not a "slippery slope" argument (a contention that we'll be banning those editors next). I'm asking how it would be worse for an investigative journalist to discover that a pedophile is editing than to discover that a murderer, rapist or neo-Nazi is editing.
Of those three, I think neo-Nazi is the most closely analogous, and I don't see why they should be allowed in Wikipedia either. As for "murderer" and "rapist", I'm not quite sure what you're getting at. If someone was convicted of murder 20 years ago and they are now out having served their time, I don't think this sets a precedent that we can ban them. On the other hand, if someone posts to message boards bragging about how they like to rape people, but that rape is legal in their country, I don't see any problem with banning them from Wikipedia.