Comment by DennisP

I'd say character is necessary but not sufficient. You also need knowledge and motivation.

Knowledge keeps you from investing in ways that mostly lose money. Plenty of young people try to do the right thing, and screw it up.

Understanding compound interest can improve motivation. Exponential functions aren't really intuitive to most people. They tend to make linear projections, which causes people to underestimate the rewards from investments and the damage from debt.

(The article of course isn't saying we shouldn't teach kids this knowledge; it's proposing better ways to teach it.)