I think the phrase "entity that actively rewards one for giving a higher probability..." made the point clear enough. If my state of information implies a 1% probability that a large asteroid will strike Earth in the next fifty years, then I would be best off assigning 1% probability to that, because the asteroid's behaviour isn't hypothesized to depend at all on my beliefs about it. If my state of information implies a 1% probability that there is a God who will massively reward only those who believe in his existence with 100% certainty, and who will punish all others, then that's an entity that's actively rewarding certain people based on having overconfident probability assignments; so the difficulty is in the possibility and desirability of treating one's own probability assignments as just another thing to make decisions about.