I can strongly disagree or disapprove of a position or person without bringing hate into it. eg. back when I was pseudo-religious and kept kosher, I was fine with seeing and smelling pork products and listening to my friends go on about how tasty pork products are, because I was completely confident in my choice not to eat them. No emotional bolstering required. In the case of Scientology et al. it's even easier to be confident, because I would have to undergo brain damage or some kind of severe personality modification before their beliefs would look plausible.

Also on a more pragmatic note, humans aren't good at separating people from their opinions. If you cultivate a hatred of Scientology and then meet someone who used to be a Scientologist but left, there's a very real chance that I would feel dislike for them purely based on their past affiliation, and that's not a behaviour I want to endorse.