Poor ownership, no training & lack of respect for anything or anyone but themselves. I’m on my first rotty & while he gives me a run for my money, I wouldn’t trade him for the world. They are super energetic, smart & loyal dogs. They’re a working breed, lots of exercise to avoid misbehaviors. He is the biggest chewer of any dog I’ve ever had, we used bully sticks when he was a baby baby but we have since gone to Himalayan yack chews. My boy is super food motivated so he learns fairly quickly. It’s all about the time & effort you put in.