Nothing says screw you like the upturned tail from the backside of a walking away kitty who will gladly eat your food and take your attention when it deems it appropriate. Cats, unlike their canine counterparts are quite independent when they desire to be, and generally wont be following you around unless you have left the food bowl empty long enough. In fact its nearly impossible for the average pet owner to train a cat to do anything but use the litter box, and even that is because the cat WANTS to. The cat is typically neat, clean, and generally knows its power.
Dogs are indeed different. Loyalty is easily gained from a dog, and sometimes even given in a way a little too sloppy. The dog will crap anywhere, eat nearly anything, but is ultimately trainable. Dogs sometimes will try to hump anything, chase their own tail, eat garbage, lick themselves and lick your face, and sometimes roll in fish, but that's OK, because they are dogs, and are excused because of it. Yes, there are smart dogs, but even some of those get hit by a car once in a while.
Dogs seek an alpha, cats ARE the alpha.
Oh.. Cats are Conservative, and Dogs are Liberal.