Idealists can sometimes get stuck in a cycle where they don't improve.

In contrast, people who are not missionaries but mercenaries need to get good at their skill to be marketable.

If they fail, they obviously need to improve their skills.

But when a missionary fails, they could tell themselves "the reason I'm not successful in the mainstream is because I'm too principled."

Idealists that congregate can form self-limiting backwaters.