Because ignorance is shamed and those who speak with confidence and like they know what they are talking about are more likely to get what they wsnt... like this comment.
Yep. In business, in dating, in life, we use the level of confidence someone projects to assess his quality as a human being. We openly acknowledge this, and most don't think there's anything wrong it.
Hedging, weasel words, caveats, etc. that accurately reflect the complexities of situations and the uncertainty inherent in understanding them ("most," "usually," "seem to,") are seen as slimy, and the people who use them are considered weak and dishonest.
I'd say the man speaking confidently in absolutes deserves more skepticism by default, but instinct doesn't seem to work that way.
I would be very careful with using the word "instinct" here. This could very well be learned, and I would say promotion of confidence over ability is more common in the US than in some other places where it skews in the other direction and false modesty is preferred.
