Hello,
I see a strong moral streak underlying many of the arguments in favour of banning this editor, with unsubtle arguments fronting the idea that paedophiles are inherently evil and can do no good. These arguments are not convincing to me; no group of people is inherently evil. Paedophilia does not lead automatically to child abuse, any more than heterosexuality leads automatically to rape. I'm sure most of us can draw the parallels to similar cases of hatred throughout history without my prompting.
We should be careful about assuming that we are the sole protectors of our underaged editors, when they are far better protected by their parents, educators, and local police. Wikipedia is a very unlikely preying ground for child abusers; it is often impossible to know the age or location of a given editor, every comment is automatically archived and logged, and even if they were to find a target on Wikipedia they would need to approach them physically. Far easier to find and approach victims in the physical world, where the underaged are common and visible. Furthermore, banning an editor does not in the least change his access to our underaged contributors.
This editor has contributed productively to Wikipedia since September 2005; he's been an active editor even longer than I have. In all that time, he has not demonstrated any interest I can see in child abuse, stalking, or harassment. He received 82% support in his request with 154 users commenting, many expressing concerns similar to mine. I think this rather discredits the suggestion that paedophiles disrupt or harm the community and project by their mere presence.
I do not agree with banning (or blocking) any editor for purely idealogical reasons, especially a long-term editor that has already proven his worth and gained widespread support in the local wiki community.