Binary brain

Conservatives think in simple binary terms.

There is black and white, good and evil and the greys between them are willed into non-existence to facilitate their world view. 

I can use conjecture by saying that keeping things clean and neat clears their palette of ambiguity. It eliminates the possible guilt of having labeled something incorrectly. The lack of nuance makes it easier to dismiss and discriminate. 

No need to complicate further.