These are the two biggest enemies of REASON;
A greedy person doesn’t use reason in coming up with a decision. Their reasoning is blinded by gain such that they end up losing much. It’s all because of greed that people get defrauded by fraudsters, get involved in casino, and all get rich quick games.
Emotions always triumph over reason. Regardless of how overwhelming the advantages of doing or not doing something may be, the person always end up doing something that disadvantages them as long as there is an emotional attachment to it. For example, a person would end up buying a car instead of investing the money in a business because buying a car is emotional.