That works if you assiduously and diligently and without flaw, start paying attention after no more than the third time you hear the idea advocated, and without using the idea itself to judge untrustworthy those who otherwise see competent.

In practice, people usually reject the idea itself and go on rejecting it, when they claim to be acting under cover of rejecting people. Consider those who die of rejecting cryonics; consider what policy they would have to follow in order to not do that. What good is it to quickly reject bad ideas if you quickly reject good ideas as well? Discrimination is the whole trick here.

I suppose we might have no recourse but to judge people and shut our ears to most of them, in the Internet age, but to say that we "lose so little" far understates the danger of a very dangerous policy.