Hating, or not liking someone for always winning when you are always losing; we can say is a result of jealousy, envy, and fact is, some people really don't know how to control themselves with issues like this.
Take a look, read the story in the shot I share below, and tell what you will do if you find yourself in a similar situation.

- will you (for the sake of peace, maybe to hide your envy, jealousy) continue to go gambling with that friend? And continue to lose your money?
- or will you tell him point clear that you are no longer interested in going to gamble with him? How are you gonna do it so he doesnt suspect that you are not happy with his constant winnings, when you are constantly losing?
Honestly I see it differently that his friend should have been able to say he's going to help his friends because he was the one who introduced him to the casino and also supported him in the beginning, seeing that the person who supported you at the beginning is suffering losses at the moment and it's been a lucky day for you, it's very normal to support him at this time when he needs it the most at least to encourage him, seeing that he still follows you to the casino even with all his losses he gets to suffer while you get lucky, that alone is even making the friendship look one sided but the other friend shouldn't hate his other friend still.