Some of the confusion here arises from not clearly differentiating between legal and moral obligations. It's perfectly reasonable to ensure that the legal strings attached to a piece of software are as few as possible (BSD/MIT/ISC, the Unlicense, or the WTFPL), but still encourage the community to hold themselves to higher moral standards regarding e.g. attribution and contributing back to a project.
This is exactly correct. It is usual in other areas such as constitutional law for organizations and groups to devote themselves to either legal xor moral obligations. The US's ACLU seldom condemns the reprehensible acts of some of its clients, for instance. Rather they limit themselves to furthering the rule of law in general. But the BSD communities tend to be small and take on both roles, for if they didn't there would be nobody else to do it. I do not think major players in major BSD licensed projects are confusing these issues, but onlookers and others often times do.
The position seems clear: 1) You can use BSD licensed software as per the generous license, and 2) FOSS developers should facilitate sharing code, including sharing reciprocally with other FOSS developers. No violation of item 2 will interfere with item 1.
By far the largest part of the past kerfuffle between OpenBSD and Linux developers had to do with violating the BSD license. This isn't easy to do, as there's not a whole lot to violate. I believe the violations were simple mistakes, due to ignorance/unfamiliarity. They were rectified after a time.
