Parents DO need to have some of the answers, but not many people can either a) have all of the answers in memory or b) create an answer out of thin air that relays satisfactorily.
Unfortunately due to the way we reproduce and the relatively random expressions of certain genes you can frequently end up with a situation where the child is so much smarter than the adult that the adult simply cannot answer all of their questions. In this case the adults only option is to eventually fall back on the "mystical force" or "just because I said so dammit". Giving up and giving in to the child is the worst possible option, but one that happens unfortunately frequently. Some of this is also some of what used to be called "lip" and warranted corporal punishment in some homes. While I'm not a fan of large amounts of corporal punishment in raising a child, in some cases it is warranted, and given whats been happening generation over generation with work ethic in most western countries you can't say that it didn't have an extremely good effect on work ethic.
That said, I was in the same boat as you, and have an IQ north of 170, which is easily 40 points + higher than either of my parents. I could speak fluently in full sentences by the time I was two and remember most things from the time I could walk at 9 months old.
The majority of people couldn't and still can't answer my questions. This is just a fact of life that you're going to have to learn to live with. Not everyone either a) obsesses about having the answers or b) is intelligent enough to just have most of them for everyday things.
The trick here is trust. My parents were infuriating because they never gave me enough answers to ever make me trust them. They didn't even TRY to give me the answers in most cases, and it was blatantly obvious.
My grandfather on the other hand did. I still have no problems doing what he wants me to do, because if he can explain something at all, he will, and if he can't explain it, I can trust that it just needs to be done and that I'll either find out or figure out on my own the why of it later.
Your view is entirely naive as #1 it won't work on a lot of people because even after it is explained, a lot of folks with iq's south of 110-120 ish won't understand WHY it is in their self-interest. Not to mention the social ramifications of societies entirely focused on self-interest are being felt world-wide, most notably in the largest collapsing economy in history, the United States of America. Your approach, while I find is actually recommended in some childrens books etc, is extremely flawed, and entirely the wrong way to go about child-rearing as a blanket approach.
P.S. Yes, I know some of this is a generalization, and IQ is NOT a perfectly accurate measure of, well, anything, its just the only semi-accurate one I have to hand.