I find it highly pretentious when people go around acting like the only literature worth the name is that which explore the human condition.
Well, I am not saying this was the purpose of literature. Naturally not. I myself have tremendously enjoyed novels which had little to say about the human condition. And that enjoyment has value, of course. Joy is the best of life, ultimately.
However, I am also inclined to at least partially agree as I mature.
Novels are about humans (or aliens, or orcs, in any case beings which are conscious) and what I would regard as a good novel nowadays often has something interesting to say about the human condition, or as Borachio says, explores it in an interesting fashion, since if it won't it usually will have crude excuses of a human as characters.
And while such excuses may not prevent a story to be joyful or even valuable in another, perhaps regarded as higher, sense, they do mark all the vast trash that is literature. Again, trash can be valuable, too. But - it is still trash. It is not just subjectivity. There is also a demand for more or less objective sophistication involved, IMO, and a state of mind which corresponds to that.
I can't imagine saying "This books got me to think, but it is so borrrrrriing."
Well, not quit what you seem to say. But my experience of reading Kafka came relatively close. Not always, but rather regularly. Yet, I enjoyed reading Kafka, regardless. Because I was so fascinated by the bits of his stories, even if the plot itself may have barely captured me.