Or, the ranking algorithm was previously designed for this not to have an impact, and as real-world usage showed abuse, they changed it. Repeat this cycle until now. So the techniques to game the algorithm changed, hence the algorithm changed, hence the stance changed... Constantly, we don't live in a static web.
(EDIT: Also of note is the fact that this change was from a year ago, and the previous one was in 2003 ... So. Yeah)
The algorithm has changed. The web has changed. Naturally, google has changed.