I seriously think this sort of thing happens because there's this idea that good, warm, loving etc people are animal lovers. And not wanting animals is a sign of being cold and mean. There's lots of fiction out there that supports this, and I hear versions of it a lot from people I know. 'I know he was the right guy for me because he liked my cat, unlike my ex', or 'My evil stepfather wouldn't let us get a dog'. There's nothing wrong with just not being into them, even if you have a house, tons of money and extra time, and no 'reason' not to.