I agree...we do exaggerate the importance of some of the changes. The book study change isn't all that big a deal, though to those critical of the Society it means more, because we want to find fault with everything they do. That's why we've pick it apart to death. We have enough to find fault with when it comes to doctrine, the blood policy, the abuse scandals; the meeting schedule shouldn't be all that important.
But I don't know if we're hyper-sensitive to the changes. Maybe some people are. Some though like to stay on top of changes so that they can keep tabs on the inconsistencies, the deceit, the out-right lies, the flip-flops, so that maybe they can help JW family/friends see the futility of remaining loyal to the bOrg.
If I know the changes before the rank and file do and I have time to formulate an opinion on why it may have happened and can compare it to past statements/doctrines/traditions it helps to see more of the hypocrisy show through. And I can hopefully use that to drop more hints with family that can hopefully jog them into questioning things themselves.
I knew about the change to the "closing of the heavenly calling in 1935" doctrine before my family. When they read it, they tried to share the "change" with me. Before they got too far, I said, "What...did they drop another date?" They were a bit stunned but quickly retreated into a defensive stance. But the seed was planted. It's there...one day it will grow.