I don't know why you've made a blanketed assumption about the OSS community. While I realize that maintaining the linux kernel may be the pinnacle representation of the OSS community, it's far from your only option. I have some colleagues that are active maintainer's of some python libraries and the boorish nature of the linux management style doesn't seem to be a factor among their contributors.
If you had a project as pervasive as the linux kernel which you have fostered for a long time and has the expectations that it does, you'd probably hold it pretty close to the chest as well. He has taken on the responsibility of seeing it through, primarily putting him in the driver's seat. If his candor doesn't suit you, the nature of the OSS community is that you have other options. It's his decision if his degree of 'unprofessionalism' happens to be running off young talent.