In gambling you only win from the start then you lose whenever you win a certain amount.
I agree gambling could consider as a sickness if you get addicted to it even you always losses and tr to recover your lose instead of just quit gambling. But if you get more winnings than lose, it's better but only happens to expert gamblers who knows how it works.
Not the expert gamblers, when one can continue with gambling even when he continues to loss he can experience the realistic facts and play accordingly in the next events which might get him easy winning. But there happens the sickness of thinking to compensate the previous losses which once again ends in lose. Easy win is possible when you are not greedy and wish to get a small earning than expecting high wins.