If you are a parent of younger children then you make decisions every day about what they are exposed to. The concern is, of course, over influence. We know that certain things (movies, music, video games, friends, etc) are impactful. These outlets can shape they way they see and experience the world. Therefore we are intentionally selective about what they see.
Pastors do a similar thing in their preaching. They look at the context and culture of their church and decide what is best in terms of exposure. They set the preaching schedule, cadence, and style off of it. As a result one of the first things that gets shifted is the depth of the sermon. The pastor (with good motives, I’d assume) keeps the content at a relatively surface level for his people to keep up and tune in.
I believe that while this is helpful in parenting and counterproductive in preaching.