The work of an actor goes beyond what we see on screen. They need to be able to do necessary preparations, meet deadlines, work with others, and serve as a public face for their show, franchise, studio, or whatever. Obviously some opinions and the character traits they reflect will influence these job functions more than others, whether negatively or positively. One employs a whole person, though, meaning that any baggage or negative attitudes come with them along with their skills, talents, and positive attitudes. Sure, they can put out the effort to filter these so they don't show up "on the job", but one can argue that that is effort better spent on the job itself. Plus, IME at least, it is only a matter of time before people show their true colors.
