I think the PostgreSQL Development Group does a great job overall. If they indeed have a reputation of being hard to work with, all the better in my opinion if it means guarding the integrity of the Project.
> if it means guarding the integrity of the Project
That's a big "if." There are many projects that have been controlled by "hard to work with" developers, and it's not always a good thing. Even if the project doesn't suffer significantly from it, that doesn't mean it's helping the project either.
That may not be the case here, but just as a general statement, you can't chalk up "hard to work with" as equating to "focused on quality" and/or "good for the project."
It's open source with a very liberal license. If someone is too difficult to work with, the rest will just fork and move on with life. Do you think the fact that people stick around, and have a respectful discussions means that the guys are not too hard to work with, and the values they provide outweigh the challenges of working with them?