Who cares.

You didn't win anything. You didn't accomplish anything. I never understood why people get so excited when "their" team wins. It literally has no influence on your life.

People get invested in the lives of other living things. It's the essence of being human.
People were invested in cavs vs warriors. People were invested in john stark vs ramsay bolton.
People watch movies and read books to get invested in imaginary character's lives and have emotional reactions- sometimes painful emotional reaction , BY CHOICE. Some people have that same kind of investment with negative emotions. I've heard of people who claim to hate certain bodybuilders, but follow them fanatically on social media and keep up with their personal lives, in what is clearly some sort of deranged homosexual obsession. Mr O's life and career have no impact on them, yet they have developed a near psychotic obsession with him.
The fact that people are willing and able to make this kind of emotional investment is a basic building block of society. If you're not into sports, fine, but this whole "I don't understand human emotions" thing that so many getbiggers are trying to do is pathetic.