Awesome article! Thanks for posting! This is something I've been saying for a very long time. Mainly because I have a sheltie who is most likely genetically shy and fearful. Through training and socialization, she has made huge improvements, but without training she would've been even more of a mess. She has never been abused or neglected, yet if she was to ever be rehomed, I'm sure people would assume she as.
This is why it bothers me when dogs who are shy or fearful are adopted from a shelter or rescue, the new owners will usually claim "oh we think he was abused in his former home." I hear that statement all the time when they dog is shy and the new owners don't really know the dog's former life. Just because your rescue dog is shy, doesn't mean he was abused. Might just be his temperament and either the original family didn't train to try to improve it or the genetics outweighed the training. At the same time, you have dogs who were abused and appear mentally unscathed. They act like normal, happy, loving dogs. Not to say that there aren't abused dogs who are fearful as a result of their experience because sadly, I'm sure there are plenty. It just seems like people automatically assume their shy rescue dog was abused without actually knowing the circumstance.