This is the case of boss not taking to such habit. Like some who have that kind of mind set that if you take alcohol then your eyes will be clearer and alertness will be high, then such person won't see anything wrong for the employees to do that when he becomes an employer. So your boss is acting very proper in such way by not allowing it. A Gamble who has the custody of money will go use it to gamble one day when he can't find a personal money for it.
I personally would definitely use the money (which my boss entrusted to me if I were in the company's finance department) to gamble because my desire control is still small
those in the finance department must have good behavior, are not gamblers and also do not have debt, so the opportunity for money to be misappropriated is very small