Some of the worst lies are perpetuated through the "Christian" genre. A few examples are as follows: the idea that Christians should not feel shame, the idea that going into the ministry is the only way to be a really good Christian, the idea that becoming a Christian will grant you some kind of immunity to suffering. These and more are the lies of mainstream "Christian" culture.
He is still an author who is a Christian. That is better, in my opinion, than being a "Christian" author.
One of my favorite examples of Christian wisdom outside the "Christian" genre is Les Miserables. That book, due to size and content, is not for the faint of heart. Victor Hugo was a humanist, which I did not know until I listened to the unabridged audiobook. Anyone who knows the actual story of Les Miserables, knows a beautiful story of redemption, mercy, and forgiveness. This was not the author's original intention, he might be horrified to know that his story had been treated as such. However, God had bigger plans for that overly grandiloquent novel than could be seen by the small-minded Hugo.
Perhaps they could appeal to a larger market if they made good content. For example, the favorite film of my childhood was The Prince of Egypt by Dreamworks. That is how you tell a biblical story, with fascinating characters and phenomenal animation. Even non-believers agree that is was a masterpiece.
It's sad to see the modern "Christian" genre descend into a such niche market that nobody really cares about. Gather up a bunch of catalogs from various "Christian" stores and I guarantee they will all have a similar aesthetic. It's the "good Christian girl" or "good Christian guy" aesthetic, Bible verses and crosses all over everything.