Liberal spec licensing was a deliberate goal of the WHATWG: remember that most of the WHATWG specs have been written from scratch rather than derivatives of the existing W3C specs (which W3C host organisations hold the copyright of).
It ultimately gives a further constraint on relevance: be relevant, or someone will fork your spec and implementers will follow.
It ultimately gives a further constraint on relevance: be relevant, or someone will fork your spec and implementers will follow.