The townspeople of Gravity Falls, Oregon had been naive for so long.
When Dipper and Mabel Pines showed up, they started noticing smaller things. They never put the pieces together, not understanding why they see these things now instead of before. After all, everyone in Gravity Falls stays in Gravity Falls.
So, what were they supposed to do when they were suddenly transported to a 'pocket dimension', as the glowing being called it, to watch what had fully happened those times they saw something? That there were more times where they didn't see or hear anything?
That worried them more than knowing they weren't going insane. That others saw what they saw. That others saw things differently to others. Everyone saw something, and yet they saw nothing all the same. It was terrifying.
So how could these two newbies to the town not have any reaction besides excitement?
Robbie knew he wasn't dreaming when he woke up one day remembering a video game character attacking him and then attacking Dipper. How had the boy won? Robbie doesn't know how to take being saved by a child so he won't mention it.
Gideon, however, was hoping to get knowledge on the journals. If he can collect the second one he could take over the entire town! Oh, he was getting giddy with excitement. Why couldn't they start already?
Stan was tense. He knows that if this is shown, it would most likely reveal him to be a fraud and a criminal. Why would he want that to happen? But it would also show the little squirts sitting next to him that he knew the supernatural existed and didn't tell them. Would they hate him for that? Mabel wouldn't, but Dipper… Dipper might start to distance himself, knowing a trusted person could easily lie to him. Stan doesn't know if he could handle that. The problem wasn't that he didn't care, but that he cared too much.
Dipper and Mabel in comparison to many around them was excited. This would prove what they'd seen true and they might get information on things that haven't happened yet! Why wouldn't they be excited? Dipper wanted to discover more mysteries while Mabel wanted to see their adventures together or separate.
And so, the town of Gravity Falls faces the screen in front of them, waiting to view their past, present, and future. What else could they do? Not escape, that's for sure.