Some people love small dogs and others like them large. I think this is a personal choice. However, larger dogs may be from certain breeds that have certain personalities that you might not find pleasing. For example, they may be territorial, protective, unfriendly, etc, and thus need a stern master. Due to size issue, it might be challenge handling or taking care of them. Think also in terms of space and finance to feed, groom and take care of their health. Most smaller breeds of dogs on the other hand, are more friendlier, they like to cuddle, playful and so on. It also takes less to take care of them.