Once it's public (even unofficially), people will begin to rely on the current implementation and then complain if it is ever tweaked or changed. They build towards the value it grants and then complain that the value was arbitrarily stolen from them.
That's for sure. I rarely visit SEO websites or forums, but the few times I did I saw lots of complaints from people who seemed to think that Google owed them something after tweaking their page ranking algorithms.
