But these changes should happen when the time is right. People need to be open enough to an idea and then change can occur. If everything comes out in the open at once, people may learn about things society isn't ready for yet.
The example that comes to mind is one my high school history teacher taught us. He said Martin Luther (from the 15th century) made an impact by being the kind of guy to question things but also by being alive at the right time for these questions to make an impact.
Not to mention that there are probably a lot of things that go on that most people (including all of us here) don't know about. Having all that come out at once might be a strain on society.