Are you asking for ONE specific legitimate reason? Say you don't trust banks, how do you purchase expensive items? Maybe you don't have a bank account for WHATEVER reason? Are you now a criminal because you don't have a bank account?

Or, are you really asking, what is the RATIO between what you'd deem "legitimate" reasons to carry money and what you'd deem "ill-legitimate"? What is the correct ratio? If we take 50% of the "bad guys" money, and 50% of innocent citizens is that too high? 60/40? 80/20? What is the correct ratio? How can you even know?