Dullness is more than a religious issue, it is a cultural issue. Our entire culture has become dull. Dullness is the absence of the light of our souls. Look around. We have lost the sparkle in our eyes, the passion in our marriages, the meaning in our work, the joy of our faith.
In Romanticism, the main determinant is the mood, the atmosphere. And in that regard, you could also describe Schubert as a Romantic.