I had a friend that approached me last year and requested that I teach her gambling because she wants to start earning money from gambling because she believes that gambling is a side hustle that can make her get more income from there, but I discouraged her from gambling because she was already seeing it as a source of income, and if I encourage her to continue or teach her how to do so, she might get addicted and lose all her money in the process. What I am saying in essence is that gambling is not a proper means to source income; while doing that, you can get addicted and lose all your money, including your salary.
She would not necessarily become addicted, but the likelihood of simply losing some of her money would not be small.
Perhaps gambling can be considered a very unstable and fickle source of money. Something like a salary bonus, which may or may not happen. Also, this bonus may turn out to be negative and will reduce part of your salary. If you look soberly at gambling as a source of income.
Do not take the winnings of other gamblers as motivation for yourself, as if you can win like them, gambling can favor people at different times, and you cannot be lucky as someone else when you think you want to win might be when you are losing.
Should the losses of other (close) people in gambling be perceived as a demotivator for gambling?
Luck is a very abstract and ephemeral thing, which is very unstable and ends up in the hands of a few. Relying only on it is very risky, especially if you observe the luck of others.
She might not get addicted, which is true, but she might end up chasing losses and continue losing her money till she spends all her savings. Since she doesn't have the intention to go into gambling for fun, I advised her against it.
I would not measure gambling winnings as a salary bonus that an employee may not know all the time that the company is going to add to their salary. There are some companies you will work with, and most of the time you will get inside information when a bonus is to be added to your salary. But when you are playing casino games, count certainty out because you will never be certain of what time you are going to lose or when you are going to lose. In sports betting, you can sometimes be sure that the game will be successful unless the team screws up.
Losses of other gamblers could be perceived as a demotivation, depending on the perception of the gambler. It could be a novice that just wants to venture into gambling (for the same reason of making money) for the first time, but seeing how often some gamblers lose their money can be a demotivating factor.