This is the equivalent of teaching a programmer to "shut up and code", even though they may have objections to the proposed solution.
I get that this is supposed to outline the differences between structured / unstructured learning, thinking, and classroom conditioning, but it's not quite fair to draw a conclusion that doesn't take that conditioning into account.
Given the environment, why wouldn't the children guess? For years, we give them homework and tests where a guess is always equal to or better than no answer at all. But that's nearly the opposite of how the world works, so we're clearly teaching them the wrong things. I don't see how revealing that is not "fair".
Teachers are much more assertive when you admit that you don't know, rather than being trying to prove your worth everytime.
Of course, this kind of maturity is hard for little kids, specially when the "differences in power" between the kid and the teacher are the biggest.
Poor kids, they are so afraid of being wrong! They would rather guess then take the time to figure out the fundamentals. They want to tell the teacher what he/she wants to hear regardless if it is a correct solution or not. I suppose that's what humans learn in a prison.
School Sucks. Enough with Civic Religion.