Relationships.
How well you get along with people is determined largely by how they make you feel. Do you feel good around a person or do you feel bad? This decides if you will keep their company.
Carmelo Anthony makes the Knicks feel bad. They might not want to admit it. Fans might not want to admit it. But he kills flow.
On some level that we can't pinpoint, he kills chemistry.
I won't even mention Baron, I think that one is pretty clear.