Blood Meridian is perhaps the easiest of his works to understand in that regard, since he's as far from deliberate occultation as he can possibly be. The philosophy in that book reaches out and punches you in the face.
If you have to be briefed on what an author is "really saying" outside of the story conveying it, what's the point?
If you have to explain the joke it's not funny.
We have English literature classes for the very purpose of finding and discussing these and other themes. The point of Shakespeare, Dickens, and Orwell aren't always immediately understood to some readers, even if they sense that there's something to be taken from what they're reading.
It's not about having it explained to the reader in a briefing. A sophisticated reader comes to a book with the cultural, literary, and historical understanding in which the themes of the book are in play. Understanding of Shakespeare's Romeo and Juliet at age 12-14, where it's commonly taught in the US, is pretty superficial. Studying it as an adult sheds light on subtle threads woven through story. What exactly are Friar Laurence's motivations in helping Romeo and Juliet? At the end, after he confesses his role, why does Prince Escalus say, "We have still known thee for a holy man"?
What armitron said was, "it's not explicit, you have to synthesize it." The verb 'synthesize' implies the exact opposite of what you've construed them as saying.