You can win from gambling from long run.Because of the house Edge you will lose if you gamble in the long run.If you gamble through poker or player vs player game you have high chance to win.But if you gamble vs house you will surely lose if you gamble long run.Read more about house edge.
Can't agree with a word you are saying.
At one side you say that bitcoin gambling has an house edge , and and the other side you mention that you can earn from gambling at the long run.
But one thing I didn't understood, how the fact that gambling has a house edge makes it profitable for the players? I think you meant to say that it is profitable to the house, who charges the house edge obviously.