Well, it's not because they have different opinions. It's because to me it feels like one of the greatest things life can offer. Just like most people would consider intimacy with a partner, having children, finding a satisfying career/hobby as great things life offers to us humans, I tend to think having a bond with an animal (cat or dog I suppose, but they're very different kind of bonds) is another thing life has to offer to us. Of course, I don't mean to imply a human is less valid without the love of an animal (or less valid without the love of a partner, child, job etc) but I still do think that some people are missing out on this. This is part that makes me sad. If you truly gave cats a shot and you dislike them, I don't give a shit how you feel about them.