Cats are cute, and you never really know what they will do next. With dogs... they are always waiting for you to tell them what to do next. So probably dog-lovers just want poor slaves that they cann order around <img src="/ubbthreads/images/graemlins/devil.gif" alt="" />
Another bad thing with dogs: the smaller they are, the more and louder they bark (in german I always say "je kleiner desto klöff"). Probably some inferiority complex.