Look at how many of us got hired as an employee or who got investment to try doing a startup and that relationship ended poorly. Are we, because we are not famous, obligated to always speak kindly of the person who paid us? Even if we perceive that the relationship turned out to not be good?
Just because someone is rich and famous doesn't mean they don't have the same human emotional responses as the rest of us; it just means theirs are more visible and open to attack.
I will never claim to know what Taylor Swift truly thinks of the Big Machine purchase of her masters. But, having made art of my own before, I do very much understand the emotional attachment to that art and the incredible difficulty in separating the art from the business transaction of making money from that art. That's something that the "money men" in the artistic endeavors don't usually seem to get.