In short gambling is for the risk takers who want to defy their luck in the game and the traders are the risk taker who will depends on the knowledge they have.
You will not be able to win gambling if you only rely on luck, especially if you are betting on balls, because this also requires sufficient knowledge about balls and having sufficient skills in analyzing matches to find out what possibilities will occur.
Between long-term trading and gambling both rely on knowledge and skills, only the level of risk is different.
We can also consider the fact that most people want an easy win without having too much effort for it.
Well… most people are like that, but it is practically impossible to win. Nothing in this world is instantaneous and everything requires a long process, there needs to be sufficient knowledge and skills and of course there must be sacrifice in it to be able to get victory. Even instant noodles we have to cook first so we can eat it.