There is an evolutionary phenomenon called “the least effort” that helped us to survive for ages. And I am sure part of the behaviour that we display in such situations stems from it. Another phenomenon is the confirmation bias (discussed by Kahnemann and Tversky in their wonderful book “Thinking fast and slow”) — we just love to look for confirmation of our beliefs and convictions rather than contradiction. On the top of it comes mental laziness — the avoidance to make things precise rather than “flaffy” and the social pressure pushing us to avoid being trouble makers and skeptics and condescending jerks;)
There is an interesting challenge though — as these phenomena are so deeply rooted in us, there is probably little to can do to alter it (at least short time). So, how could we work alongside them? Make use of them in getting better definitions and better decisions?
Thank you, Chris, for this thought-provoking comment!