I think the rate of change in the Church is rooted in the principle that the tree only can be pruned according to the strength of the root. Traumatic surgery kills as often as it saves - especially if minor surgery is enough for the moment. I think the church's global leadership believes this and uses consensus as a means of not endangering the tree as a whole.
To use a different analogy, the band can continue to play on an ocean liner that is turning continually, but when a speedboat switches direction suddenly, passengers can get thrown around violently and even go overboard quite easily. I think there is an important purpose behind changing course only with consensus, and it is rooted in a concern for the safety of the passengers and not risking the boat capsizing.
Our history supports this position, frankly. Sure, Joseph's time was free-wheeling and exciting - but it also had the most schisms and most active, violent, dangerous persecution. It might appear to be exciting and appealing as we look back upon it, but people generally sank or swam - or died in the process. There is a time for explosiveness and sudden change in a young, evolving organization, but if such radical and constant change continues, those organizations tend never to mature - or they die. I understand the allure, and I would love to see more radical change in some areas, but I understand that it can't happen too quickly.
I think the world-wide training when the latest Church Handbook of Instructions was released is a great example of significant change accomplished gradually through consensus.