I think your comment reduces to "The board of directors controls a company, and shareholders have the power to vote for members of the board of directors". I agree. And before this event took place, 59% of shareholders votes were held by Sergey and Larry. This means that Sergey Brin and Larry Page held the majority of shareholder votes.
With great power comes responsibility. With a 59% interest, Larry and Sergey had absolute power over Google, and therefore absolute responsibility. Perhaps the move in China led some to believe that this is too much power. 52% enables the remaining shareholders to overrule Larry and Sergey's decisions -- in theory. In order for this to occur, virtually all the remaining shareholders would need to reach unanimous agreement against a decision made by Sergey and Larry -- highly improbable, but possible. Without absolute power, there is no absolute responsibility. Conveniently, this also aligns with a liquidation of billions of dollars.