I struggle when people do not appreciate great art because I believe that beauty is objective.
I struggle to define that standard. Yet even so, when someone tells me that William Shakespeare was simply "meh" or Michelangelo was "just a sculptor", I cannot accept that opinion as legitimate. These artists were geniuses, and to say otherwise is downright wrong.
Everyone has different standards of art because they were raised in different situations by different people. This applies in every area of life; we prefer different food due to growing up with certain norms, prefer certain temperaments, prefer certain environments. But simply because someone likes "Call Me Maybe" better than Beethoven's Fifth does not mean that "Call Me Maybe" is higher quality music. The problem is with your ears.
I submit that we have numbed artistic taste. The problem is not with Macbeth or "The Pieta" or Beethoven's Fifth. The problem is with us.
I don't claim to say that everyone should like every form of art. We can't change our tastes on a dime. But we at least need to acknowledge that maybe we're not ready to digest such a high form of art because we're used to mediocrity. We need to acknowledge greatness, and be humble enough to admit that we may not be ready for it. And if we can bring ourselves to do it, seek to grow in order to enjoy and appreciate that beauty, as dull as it may seem to our dull taste buds today.