But even with those ideals in play, why would a millionaire start gambling in the first place?
Each person can have a different goal when he/she plays gambling. Not everyone plays gambling for money purpose only. Some people gamble for fun, they like gambling because they get entertainment while they are trying luck to earn money as the bonus. A millionaire may be interested in gambling because he/she wants to have some fun with gambling games. Sure, they don't deny the prizes but it won't be everything for them because they have enough money.
so why would a rich athlete or politician become so addictive to gambling?
It is because they make it as their habits. If an athlete or politician have played gambling games daily without a limit, it is easy to be addicted. Basically, it is about how they gamble, it is not about their profession as an athlete or politician. Everyone who gamble with inappropriate ways, they can be addicted to gambling. So, makes sure that we apply the way in gambling.