"Okay, maybe the sun rises at 8AM and sets at 4PM but you get an hour of dawn and dusk at each end, and maybe build a fire and stay up for another couple hours - so that's 12 hours. And then read a book with flashlight for a couple hours or look at stars..."
Depends on what you are doing during those hours of dusk and dawn. They are often the coldest, and the only way to keep warm is zipped up in your bag. Often it is too cold to even have your arms out to read a book, at least that has been my experience.
And a fire is great, if you can start one. A lot of our trips end above bushline, or in wet snow. Not the easiest places to get a good fire going. However, if you are going to be below bushline and not a lot of snow around (and everything isn't soaking wet), then that is a nice option.
However, there is also another really good reason, at least for me, to only stay in huts in the winter. No winter tent, no winter sleeping mat (so much lighter pack), and no worries about boots, fuel and water bottle freezing. Plus I find it almost impossible to get comfortable enough to read while sitting or lying in a tent. I don't mind some degree of discomfort, but with winter camping I draw the line. By drawing this line I can hike 12 months of the year without making excuses to NOT go, but, as I said, not everyone has a choice of winter friendly huts to aim for.