Part of the Facebook problem is that they mostly took control of the feed away from users. They now surface the more "engaging" posts at the top and more frequently. This leads to the overemphasis of viral images and videos. If you post a simple personal status message without an image and Facebook's sentiment analysis considers it to be non-engaging many of your friends won't even see it as Facebook will favor marketing spam over your actual personal post. Users also become trained over time by the number of likes they receive to tailor their posts to conform to Facebook's whims.