There seem to be two kinds of cat-dislikers, those who just dislike them, and those who think you have to choose cats or dogs, and think dogs are clearly superior. For those who think to love dogs must be to hate cats, I can only say I hope they never have more than one child. I know dogs are very overt in their affection and loyalty, while cats are less so, but if one observes with unbiased eyes, cats are also very affectionate, just in a quieter way. Cats are less active overall than dogs, which may be why some people downgrade them relative to dogs.
There are a lot of stupid myths and superstitions around cats, which may have affected some people's attitudes. I remember when my daughter was born, my mother-in-law (who was a real piece of work, but that's another story) was appalled that we weren't getting rid of our cat, for fear she would suck the baby's breath and kill her. Cats were a commonly presumed witches' familiar and even today are associated with witches and Halloween. Cats are said to be "bad luck" and to be able to curse people. All of it is patently absurd, but some people have internalized the negative attitude, even if they don't accept the superstitions