Why does boss want me to lose my hair?

He keeps laughing that I'm going to lose my hair working there and my nice hair will be gone by next year. They really instill an environment of competition and stress in the workplace and I try my hardest to not go down to their level yet they enjoy having unhappy overworked and stressed employees. I am not complaining but more curious as to the mindset and their viewpoint that makes this something they get off on