I think of all the online habits to take to task you picked probably the least annoying feature of the most-loved social platform in the world right now. It's not that hard to un-pin. You don't even have to un-pin, just keep scrolling. Any chance you'll expand on this rule beyond "they annoy us"? Something about user-experience and the risk of monetization for social networks? Or maybe we need a new rule: you log one-percenter complaints, we unfollow.
It gets a little dicey the more tumblrs you follow. But you raise a good point. We don’t want our tumblr friends to lose out on any monies. With that in mind, we’re announcing a last-minute moratorium on all unfollows related to pins while the nwktumblr legislature has more time to review the policy.