This is the same with "gambling must only be for fun and never for serious matters". Must agree.
People should really treat gambling that way.
I mean gambling is not something that people should be serious unless you have the ability or skill to be a professional. It doesn't mean that you can win games by yourself, which means that you can also be a professional.
Greed is a bad thing and many people come under this influence and just to make quick money they gamble a lot and keep playing till they do not make good amount of money or till they broker down . Only those who have control can quit this vicious circle .