The quality of the meat suffers, too. Sure, this is a problem for pigs and for pig geneticists like us. But the ones that are really being hurt by the failure of pigs to express their genetic potential are the pork producers. We're only interested in gentleness as it affects economic performance. We simply want pens that produce more meat at lower cost.
Bullies exist in the animal kindom.
And when sociable creatures encounter domineering ones, there's always a high level of stress. Next, they developed, refined, and expanded upon the theory. Finally and most important of all, they reduced it to practice. They discovered a way to implement this breakthrough genetics program in a commercial setting. Otherwise, purchasing genetically improved breeding stock isn't a great deal at all.