[quote=@Raineh Daze]
<Snipped quote by IncredibleBee>

Simple altruism. Distaste for the other missions. Hearing it before hearing the others. Judging the people doing the urgent stuff more than sufficient. Unless something is directly against a character's beliefs, coming up with reasons is trivial.
[/quote]

Coming up with reasons why a character would do a thing is actually essential, though. It's the point of a character.

Even people themselves are basically big balls of incentives.