If we believe that gambling is for entertainment and thus capable of bringing happiness, why do we also claim that it is not a part of our daily expenses? In my opinion, the reason for settling our expenses is so that we can live comfortably, and if gambling can add to our life span because anything that brings happiness can increase life span, why do not you classify it as living expenses? We must recognize that some of the bills we pay yield no returns, and that if gambling is done for pleasure, it is rewarding because nothing should be equated with an activity that produces happiness.
Yes gambling is definitely for entertainment and capable of bringing one happiness, but that doesn't mean gamblers shouldn't have or get involved with other activities that can also make them happy and increase their lifespan too.
Gamblers should also maintain a balanced life and get involved with other activities that'll give them the same kinda fun and happiness they also derive from gambling. We can't really predict the future, just because someone is gambling responsibly today doesn't mean he can't get engaged in irresponsible gambling tomorrow, completely relying on gambling could actually lead to an unprecedented unhealthy obsession, could even result to neglecting of one's responsibilities and even lack of personal growth.
These are likely to occur, hence the reason why gamblers should try to strike a balance between their gambling habits and other things, considering that gambling can be very addictive, we must regulate how often we gamble.