I could say I don't like agenda-driven literature, but then I wouldn't be reading anything. Everything is agenda-driven, depending of course on your definition of "agenda". Whether it's agenda-lite or agenda-heavy depends on that definition. But the agenda is definitely there. I readily confess I write with one.
If the agenda speaks to the reader you have in mind, you have writing success. Those who don't - or won't - appreciate your agenda aren't your target audience. Another way to discuss this "agenda" is simply by stating the authors have a point they want to make. Whether it's the hope of happily-ever-afters or that terrorism is real, whether they "just want to entertain" or they want to "present a possibility", the purpose of fiction is to traverse the gamut of reality, surrealism, fantasy, etc., in story form.
Addressing social issues in novels is age old. It's a risk because some don't read fiction for an agenda-heavy experience. The target audience is established by the particular issue, and it conceivably could be a smaller group of readers whether it should be or not. Authors who have an established following can throw in an agenda-heavy novel successfully. How it will be received is anyone's guess. Some readers will praise the effort because it focuses on a topic they view as important. Others will quickly close the cover after the last page and attempt to file it in their not-so-fond-of memories.
When Christian authors decide to deliver the gospel in various ways, they are basically writing for those who either are believers or who are not closed off to things of God and are aware they can count on "clean" books to read in the overall genre. Secular humanists who pick up a Christian novel are generally the first to be "offended" by it. They want no suggestion or mention of prayer, God, Jesus, certainly not the Holy Spirit, and if agenda-lite, where these factors are barely there, they most likely won't recognize the godly principles presented throughout the story. If they do, they tend to resent them.
Authors must take a stand. Especially Christian authors. By that I mean define who they are in their literature. Do what they were created to do and do it well. Make statements in characters, circumstances, emotions, locales, everywhere and in everything authors need to proclaim reality, truth, sin, and the consequences of it all. Real life demands it.
Father, you are what we all need. You are The Creator. You are Life. You are Love. We need you more than we can ever know. In the Name of Jesus, Amen.