We will have different opinions on this. The only problem I see on his point is the tone of being discriminative and conclusive. Everything is a matter of what works best for you. It all depends on how you view being rich is. Some became rich out of their profession, some are with investments and yes there are also people who made fortune in gambling. Determine which method will work on your circumstances. You could gamble without desiring of becoming rich as well; just a source of entertainment. We all know the importance of investments. However we have different pathways and goals to achieve in our lives. You could choose or create your own route. Not all investors became rich in the first place and same goes with other gamblers as we all know.
The desire to profit from gambling can only end when you are playing with someone else's money just for fun and that money is not your own and you will not be sad to lose it or if lost, you will not try to recover it. On the contrary, I don't think that no matter how rich someone is, he will not regret losing millions of dollars on gambling and he can live in peace by gambling only for fun.
Wise people will never waste their time and money on gambling, because there are thousands of things to do in the world, from which we also get benefits and entertainment. You will never lose a lot of money. Gamblers understand very well that once you start gambling, you can lose half, if not all, of your money, and I think there can be no fun in a thing in which you have to suffer a loss, and a loss which you were not obliged to get.