Gambling is just many other businesses that involve risk which is why it is advised that we should gamble with only what we can afford to lose.
It's different, in gambling you stake $100, you might loss the whole $100.
In business, you will buy products, even your business aren't working like what you expect, you can still sell your products, you not lost it all.
some persons don't even win at all within a year then why having such mentality of making money through gambling
What's the definition of win?
It's impossible someone didn't win at all within a year, you gamble on slots, there's always a win after you gamble for few bets. If you refer to profit, I'm sure any gamblers are in profit as long as they know when to withdraw/stop.