I've worked in non-profit organizations that rely heavily on volunteers my entire adult life. I can't imagine not responding to a volunteer who has offered to help, even if it is just to let them know that their help isn't needed at the time.

It appears to me that Joe Offer is saying the volunteer offers to DT are seen as a hindrance rather than a help. I understand the importance of the editing job being in only a few hands. And that this is a grassroots effort, not a professionally organized one, so the accuracy and usefulness of the database is less of an issue for me. I don't expect professional standards here, because the DT never claimed to be that. But there is such a thing as basic courtesy, that no grassroots effort can afford to forget about either.

Just another two bit opinion, of course.