You cannot.
Because gambling takes no brain, no skills, nothing required to play it. It is only about luck.
If you want to be a successful athlete, you need to practice. You need to educate yourself. To be a successful gambler, all you need is luck.
That is too much to say that gambling takes no brain or skills, we have some professional poker players that use their skills to win. I concur that some games are only based on luck but there are other games that will test your knowledge and skills
But for the topic I do not think it's going to happen, gambling has been seen as a bad thing for centuries. This quo-notation has been influenced by religion, media, etc. There are things that we cannot change and I think perception in gambling will not change.
some people are using gambling as their recreational activity and they don't think too much about to win the games. all they want to do is to enjoy the game, they don't expect to be a winner but if somehow they are winning, then they will consider this as a bonus for them. I have seen a person that only gambling for searching a fun and I take a look in his games, he play a poker too in facebook and he makes a lot of chips but he doesn't think about selling his chip or cash out the chip (if he can). he wants to use his time with his friends in the table and he can control his emotion while he does not win.