Small dogs usually have some degree of terrier in them, so that makes them kind of yappy and obnoxious by nature. People tend to neglect their training because they are small and usually can't do much harm, even if they are ill mannered. Still, it's almost impossible to get a terrier to be quiet. It's instinctive for them to raise a ruckus when strangers (or critters) are running amuck - in other words, anywhere nearby. Difficult to get them to suppress this behavior. OTOH, it is NOT hard to train a small dog not to growl or snap at people. That's just bad ownership. As well, these dogs need to be indoors when not supervised. Since they're small it should be easy to do. Failure to do so = bad ownership again.
Working breeds are bred to listen to you, so training them is as easy as falling off a rock. Terrier breeds, not so much. Anyways, I like small (but not so small as to be toy) dogs. It would be nice to have a mini-lab type of breed though. So 20-25 lbs of sweet mellow obedience. No such thing that I know of. Corgis and Shelties are pretty well mannered small dogs though.