They certainly have good reason.

[Whatever they fled from is obviously not the same as whatever is in the forest. Maybe they're not even similar. But when you've had to flee one home already, maybe you're more...cautious, after.]

The original members of the Galaxy Team came north from Johto after their village was destroyed by rampaging Gyarados. Their former leader was always so paranoid...about everyone, certainly, but especially about Pokemon.