Not the message, but the fact there's little else besides the message to keep you interested.

As opposed, for example, to Richard Morgan's A Land Fit for Heroes. Where the main character is gay. He was persecuted for being gay. There are gay sex scenes.

However this is not what the book is about. Stuff is happening in that series. He's the hero of a decent story.

But then I'm talking about a fantasy series so it's not "literature" :)