This can also be translated into everyday life, if a person has a differing perception on a situation, is it my place to believe their perception is incorrect because it differs to mine? Is there actually a reality or just differing interpretations? If we believed there was no reality, would we be more tolerant of peoples perceptions and "walk a mile in another's shoes" before judging them? If you think you are a realist, to whose reality are you basing your beliefs on?
Have a look at this painting, do you see a weeping women? I didn't, until a friend of mine pointed her out to me. Maybe she was meant to be there all the time, but I know I did NOT paint her into the canvas. She is not a reality because you may not be able to see her. What do you see?