The short answer is because it is done by volunteers and there are only so many hours in the day outside of work and other obligations. And it is really hard. If you take into account the machine work needed, there were probably 40 hours of volunteer work put into what you saw groomed. Over five just in the grooming.
Longer answer: Everything that is going to groomed was groomed by Tuesday night, knowing more snow was coming. But getting a base was key to be getting everything groomed after the next snow.
The Rokon does not do well in deep snow. Last night three of us spent 4 1/2 hours, over 12 hours of labor, to get the trails groomed again. The snow was really deep and hard to get through pulling the groomer. I am sure it will be a couple of days before my sore muscles are gone.
There is a lot of CamRock III that is not groomable in this deep snow. Hills are impossible to get up.
Feel free to snowshoe groom the rest.