I think that the point is that believing in the Great Pumpkin that hard is inherently absurd, and if you're going to carry on shaping your life around your belief in it, you should understand that some other people will think it's absurd, and steel yourself for some ridicule.
I think breaking into people's stuff to mock them is being a pretty big asshole, but I don't think it's worse than being an asshole.
The problem is that when people get into things that hard they tend to only 'stick to their own kind.' It's really easy to be sucked into things really hard like that when you're only around other people that believe in it that hard. Why do you think that most cults have compounds, and that in some cults you're not allowed to talk to outsiders?
I think breaking into people's stuff to mock them is being a pretty big asshole, but I don't think it's worse than being an asshole.