Both sides have their points: some don’t believe, and others do. We just need to respect each other and never say it’s impossible to be profitable in gambling, because if you think that way, maybe gambling isn’t for you.
The reason why both sides tell that it is profitable and it's not because it's based on their experiences. While it's true that we have to respect each others opinion but we also have sometimes include it with reality. If someone tells that it's impossible to be profitable in gambling, that's their opinion and we can understand where they are coming from and why they have a mind like that. And that's because they've lost so much when they've tried to do that for themselves.