The decision is never go or not. Risk is not a zero or one decision. Stay home if you want absolute safety. Regarding the decision as a pro pilot, you are right on. The pilot must decide on the basis of fuzzy information if the risk is worth it, and sometimes he faces a tough Ops manager or boss. The most unhealthy situation is when the guy in back second guesses the pilot. By and large, old pilots know that is the time to move on.