I would see this a lot, too. I think in many cases it is a coping mechanism that they develop and may not even realize they are doing it.

You see articles about not praising kids for being "smart" because that praises something innate about them, but instead praise them for working hard or growing or learning. Sometimes kids that are "smart" in middle school don't have to work/learn/study because everything just makes sense. But then they get to high school and their grades start to dip because their "middle school smarts" don't apply to high school material and they didn't develop the skills to study/learn effectively. But they are known as "smart kids" and smart kids get good grades... So they need to find ways to get good grades... because they are "smart kids"

I hope I was able to help some of those students unlearn some of those habits and develop more educational ways to "get good grades"