Seems reasonable

Conflict *is* inevitable, and it is realistic to expect it. The goal should be conflict resolution, not the elimination of conflict. I'm sure the document can be improved, but it doesn't strike me as unreasonable.

I tell people to be harsh on the code, and kind to the people. It's important to separate code from people. Yet it's really hard to do that separation.

People's lives literally depend on the Linux kernel in some cases (e.g., a 911 call using Android). I suspect some kernel developers are concerned that a community focus on "nice" could lead to a failure to rigorously question the code (after all, many communities DO overlook performance failures in order to be "nice"). Does one kind of niceness necessarily lead to the other? I don't think it needs to, but I suspect that is at least in part one of the underlying concerns. The Linux kernel developers are clearly focused on quality of results (as illustrated by the first part of this document).