"I work remotely, and don't really understand why it's hard to shut down the work-laptop after you finish work and not open it again till you start work the next day."

The key phrase there is "after you finish work". For some people, that point is not clear. Also, for some companies, your work laptop might be your laptop.

"I guess I can see why some folks would find the balance hard in the "life/fun" end being too heavy and fail to drag themselves to the keyboard for 8 hours a day."

For me, this is one of the things that I was worried about. Currently, there isn't a good place conducive to getting work done in my home.