Parents shelter their children simply because the child is not mature enough to handle the cruel reality of life. When politicians and governments shelter their citizens, they are saying that the people can not handle the truth. The issue becomes whether the populace can be trusted or not.
I find that what is hidden should never happen in the first place. What is hidden tends to be tragedies, injustices, or just plain wrong doings. That is why people must be sheltered, to keep them calm, peaceful, and in ignorant bliss. Gives those in power a relatively easy life, which isn't exactly a good thing for the people being wronged.
If the governments and politicians were clear, then people would know what is actually going on without having to deeply research something that they simply don't have time to do. Everyday people have the right to flat out know what is going on without being led in a round-a-bout. Then maybe there would be some morals in government.