It's said that people rise to the level of their incompetence. Some leaders might see this and think, this guy is dangerous and we can't have that. If I were a leader at his firm and I got that email I'd be thrilled. If everyone admit their limits and thought like this all companies would run more smoothly. He rises to the level of maximum competence, the perfect place for him, he won't be bitter about not getting the next promotion and cause trouble by leaving for seemingly greener pastures, and he will be reliable in handling his work load because he's comfortable with it. People like this are valuable assets in an organization, it's a shame that a lot of people don't see it, they look upon ladder climbing as admirable, but ambition is about taking you where you want to be, recognizing when you've achieved that is much more admirable.