Gambling can be only profitable if you are lucky and the chance is really low that you can make some profit with gambling because the chance is just to be lucky to win some money.
And the chance is really low that it can be profitable for you because losing is a higher chance.
I don't think it's down to luck purely, some thinking and self control also have a big part to be profitable in gambling. Skill is also needed in gambling so you could "beat" house edge, and use your self control to end your gamble while you have your profit.