The funniest counterexample I know is Jefri Bolkiah =)

If you didn't delay gratification and had expensive tastes, you'd spend the money quickly, regardless of how you got it.

Even if everyone did have expensive tastes, people who started off with less money would need to delay their gratification more. A very poor person might need to delay gratification an average of 80% of the time, since they couldn't afford almost anything. A sufficiently rich person might only need to delay gratification 10% of the time without running into financial trouble. So if you wanted to reward delaying of gratification, then on average the poorer that a person was, the more you'd want to reward him