This is predicated on the idea that monkeys can't transmit culture through any means other than direct observation, and that no record is able to pass between generations of "why you don't go up the fucking ladder" other than the plainly observable "When a monkey goes up the fucking ladder, all other monkeys beat them up" And maybe it's correct for monkeys and very small children who need to learn that fire hurts. But in human society, we have other means of transmitting information, and while you're bound to re-derive a few basic things for yourself, it's damn impractical for every human to re-derive everything. We move forward, generation through generation, by standing on the shoulders of giants, and that's fine.
This isn't to say that one should not occassionally re-examine his beliefs. Especially when there's not a well-founded and logical basis, questioning whether something should be done a particular way can be valid, and it might be possible for the individual to quickly overturn or reaffirm for himself the traditional 'wisdom'. Sure. You need some of that, but it should be with reason and in the spirit of careful consideration, not arbitrarily because "that's just what some people think, man."