I can't have anything but a viseral reaction to your entire post. Critical thinking should be taught as early as possible, its habit, and you want to get good habits ingrained as early as possible. Brains are not really even capable of critical thinking until around age 8, so its a great time to stuff heads with rote learning like multiplication tables I agree with you there.
But by the time you are teaching history and algebra you should also be teaching critical thinking, because the two are all related. Your write protect bit concept is a off base too. Teachers at those subjects should be able to earn the respect of their students, enough to at least trust the information if not the opinions. If a teacher can't do that they are the failures.
Most our societies problems stem from blind trust of authority and people not engaging in thinking let alone critical thinking.
The "if you like your insurance you can keep it scandal" is the perfect example. It does not matter which side of the political debate you come down on. Everyone listening reasonable should have know in the context of a bunch of new requirements many even most current plans did not offer this statement was some place between a lie or incomplete. Instead three years later a bunch of people seem surprised and last moment measures have to be taken. Why because people don't think...