HN's title policy hasn't changed since 2012. People sometimes mistakenly think we say to use the original title no matter what, but that's never been the case.

If we allowed linkbait in titles, the threads would mostly be about linkbait in titles. This effect is strong, reliable, and immediate. Therefore we don't allow linkbait in titles.

As for "unless we feel like it," nothing could be less true. The way we edit titles isn't algorithmic but it's at least semi-objective, and you'd be surprised at how meticulous we are. It's easy to defend in nearly any specific case (we make mistakes, of course, but that's not a policy), which is why when people complain about it, they tend to either kvetch vaguely or use inaccurate examples.