And that's why always calculate the risk that you're taking. Not everyone is good in taking risk and if some are reckless in taking risks, they'll earn it sometime in the future when they've learnt how to control themselves being reckless. At some point, there's a pros on it because they are not scared in taking more risks and new risks that they can see and that's why if someone is up for taking risk, little or high, it varies based on the experience and thought that they have. Some are playing safe and will only take what they can afford to lose.
Personally, I would disagree here that there are any pros to taking high risks in gambling.
Yes, taking on beyond what he can afford to lose is a good choice for having fun on gambling but if he takes on risk of funds that are more than necessary or that he cannot afford to lose, then it will be nothing but foolishness, but rather he will see cons instead of pros, such as increasing debt and loss amount together.
Overall, I think it's best to take as much risk as you can get from gambling, not that amount where you will be in stress.