He was kindhearted, in a way. You know the sort of kind heart: it made him uncomfortable more often than it made him do anything; and even when he did anything, it did not prevent him from grumbling, losing his temper and swearing {mostly to himself}.
The character described is depicted as having a kind heart, yet this quality often leads to discomfort rather than action. His kindness does not translate into consistent positive behavior; instead, it is more of a sporadic trait that he grapples with. This internal conflict illustrates a struggle between his good nature and his human flaws, which can manifest as irritation and anger.
Even when he tries to act generously or kindly, his grumbling and cursing show that he is not entirely at peace with himself. This duality highlights the complexity of human emotions and behavior, suggesting that kindness can coexist with frustration and imperfection. The character’s journey reflects the common challenges of maintaining a positive disposition in the face of life's difficulties.