1) Have you ever considered gambling as a means of generating passive income for yourself?
2) Do you think it can become a source of reliable passive income for you?
1. Gambling will never be a passive income. A passive income came from doing nothing literally as we already set that source of income to sustain its generating money scheme without putting more effort.
2. Gambling can't assure us an always win. There should be less risk for something to be called reliable, but that's not possible in gambling.
Can you explain in what way can gambling become a passive income?
I definitely agree with that, the OP used the wrong term because passive is described just like you mentioned above. Also, gambling can never be a sustainable incoming whether if someone is a professional sports bettor or gambling, the risk is the same as playing in the casino and betting in sports but the twist is that we need to analyze the facts carefully in sports but even that won't guarantee our win as it's not a simple math we're talking.