Some students get tempted so they'll gamble pocket money their parents gave. It's wrong they shouldn't do it but there's pressure to buy expensive clothes & phones they want to look good to their class students. If they're educated about savings & investments it's going to help them when they get their first jobs.
As an adults we understand how important education is, but when we were kids, we did everything possible for not to study. As we were kids, we cared about nothing. What people write here (especially the guy you quoted) is a description of a perfect life in a perfect world, where kids only study, do sport, and are kinds. Many, who are 40+, dont understand that kids now are different from when you were kids. Moral standards have changed. If gambling for underaged was inappropriate 20-30 years ago, then today its our reality.
I also like how adults discuss importance of money and investment for kids. That they want to introduce them investing as early as possible so they could build their future from early ages. But somehow they forget about risk and luck factors in investing, and talk that gambling is a big NO for kids. Kids should be able to risk in investing from early age, but should not risk in gambling until 18. Even though gambling does not equal investing, both are risky.