Actually, Greed is not only the cause of losses in the gambling it is the cause of every problem in every where for example I can say also the trading where people were also goes by depending on the greed and as well also face the losses.
And that's why greed is bad in every aspect.
Whether we gamble or we trade, it's not going to give us some good results.
Because in the end, there will still be bad results that we should have accept in that term and so these losses are deserved by a greedy gambler.