A person can love AxB and BxC ship at the same time.
A person can love AxB but hate BxC at the same time as well.
But a person can also like BxC couple as A type of relationship, but feel extreme distaste in them as B type of relationship.
It’s a natural thing really. For example, I’d love to see A&B going out on a fightey-fightey date, acting like brothers and sisters. Their interactions are enjoyable.
But on the other hand, I’d be very displeased to see them as mutual lovers who croon over each other.
Some people may hate A&C as lovey-dovey lovers, but neverthless they get excited&happy and empathize when they see those two set in some angsty situation like where they have to harm each other for the sake of greater good.
It’s not because they hate that A&C relationship. They just have different way of liking it. (I’m not mentioning which ships they are, but these are actual cases I’ve seen).
So it ends up bringing situations like “Hey did you see that latest C&D shippy scene?” and one’s reaction could be like “Ergh, I didn’t like that at all even though I like C&D a lot.”
Human minds are so picky, really.