In my opinion , gambling is not wrong but the wrong is the player while they can't control their emotion or limit their profit.
And if you really addicted with gambling while you usually win on longest streak and becoming greedy , it's the sickness of gambling players.
That is the most reason why gambling is really wrong, even with players controlling their bets they will eventually realize that gambling really is nothing but mare coincidence and luck if they will keep on playing it they will end up losing so much that their entire savings will be all gone! Well to tell you the truth gambling really isn't for people with losing much to their emotions and actually that is the side effect of the wrong doings of a gambler and gambling is really wrong wherever you look at it.