"Conspiracy theory" has a very simple meaning (http://en.wikipedia.org/wiki/Conspiracy_theory) and no derision at all. You might take it as belittling but it's not. The term "conformist" on the other hand fits your description perfectly.
Come to think of it, "belittle" doesn't exactly capture what I meant, which is to mark someone as outside the zone of proper discourse. I will change the comment.
No derision at all
That's obviously not true. If it were, people would use the phrase to describe their own views sometimes.
No derision at all
That's obviously not true. If it were, people would use the phrase to describe their own views sometimes.