Does the license not allow forking it with group of people more interested in accepting contributions? It has a bunch of users. If my theory is wrong, it should've forked with a lot of updates by now.
On that very email chain, once the sitution was stated and as Bill kept on ignoring everyone as he did over the last year and a half, the community hard forked FindBugs and started aligning behind https://github.com/spotbugs/spotbugs
Bill's reappearance is now puzzling. To abandon the fork to go back to FindBugs would require major leadership changes, as confidence on Bill has been shattered. Keeping the fork leaves the project on the same point people tried to avoid in the first place.
Sounds like quite a few precautionary tales in this one.