I think there may be an issue here where the two perceptions of the world are both right. For people with pain avoidance tendencies the part of their brain that

I think there may be an issue here where the two perceptions of the world are both right. For people with pain avoidance tendencies the part of their brain that creates reward may actually be damaged. So they can only avoid pain as there is no/diminished reward for them in completing a task. The feedback loop for people avoiding pain may be different than the feedback loop for people who are chasing a reward. This would be really hard to understand both ways if you had only ever experienced one or the other.