Gambling can be profitable in the long run, provided we are not greedy or seek greater benefits than we have get. Profit 1%/day are better than 100% but only once.
How let's say you deposit 1 btc to gamble and don't win anything so you can't call the person greedy in this case.
Basic rule of gambling and it applies to anyone who gambles 'Deposit only the amount you can afford to lose' if you follow this rule you will either not gamble or if you lose you may not have any regret (hopefully)
If the game your are playing does not require skills like poker, and you are playing against the casino, you will eventually lose due to the house edge advantage. I agree, better play only with the money that you can afford to lose and only for entertainment.