There are plenty of examples of "Choosing knowingly" being frowned upon by large segments of society. I can think of at least four:

* In large segments of society, you're not supposed to accept or reject a religious belief system by choosing knowingly. Religion is instead supposed to be a divine revelation.

* Patriotism frowns on anyone who honestly tries to figure out which country is the best (or which side of a war is right.)

* Love is considered more virtuous by many if blind; you're not supposed to decide to fall in love with someone based on rationally considering that person's merits. It's supposed to be mysterious and magical. (Similar to the religion example.)

Note: The theme running through these examples is loyalty. We value loyalty, but some see it as somewhat incompatible with choosing knowingly. While loyalty to a goal goes hand in hand with choosing knowingly, loyalty to a belief does not. To the extent that those untrained in the art of rationality tend to mix up "is"s and "should"s, they will feel that loyalty is incompatible with choosing knowingly.

* Last, there are plenty of popular stories about people who succeed because they "believe in themselves" and very few about people who fail to do something despite believing in themselves. I remember getting into an argument with someone who said "if you really believe in yourself, you will win."

I replied "What if there's a competition winnable by only one person, and *two* of the contestants really believe in themselves?"

I think they tried to weasel out of it by suggesting that there might be more than one race held and that the contestants could take turns winning, or something like that.

So parts of our culture seem to value believing in yourself over knowingly acknowledging ones weaknesses and then picking a realistic course of action. (And of course, "acknowledging ones weaknesses" is also an applause light...)