Delicate Motor Gator can’t plow snow without damage unless there is at LEAST 4 inches

I think this reporter isn't having a clue... Bolding is mine. Gater. Really? Am I missing something? http://www.nbcmontana.com/news/Bozeman-residents-wait-for-roads-to-be-plowed/36747688 BOZEMAN, Mont. - Jane Hawks has lived in the same house in Bozeman for 26 years, at the corner of two residential streets. She's waiting for city workers to clear her roads of snow and ice, but the city does not plow residential streets until at least 4 inches of snow accumulate on them. Hawks said, "Most people who live here have snow tires or some means to drive through the snow, but 4 inches is quite a bit of snow." One piece of equipment used to plow through residential streets is called the motor gator. The city says it is expensive and delicate machinery, so they have to be very careful with how it's used. If they plow snow less than 4-inches deep, the motor gator can be easily damaged. "We're going to concentrate on getting people to work, to home from work, getting them to the businesses and shopping areas. We get those major streets done first before we get into the residential areas," said Bozeman street superintendent John Van Delinder. Bozeman has about 150 miles of residential lanes. It takes Van Delinder's team about two or three days after they first start plowing the major roads to get to the residential streets. He said they can't do them all at once because there is not enough manpower. Residents we spoke with said they don't always see trouble with the roads. They said the problem comes when it starts to get warm and the roads defrost then refreeze overnight. The roads become slick and cars can slide much more easily. "When the snow comes for the first time, people seem to forget that you can't go at the same speed that you do in the summer. We seem to have to learn that again every winter," said Hawks. There's no set schedule for when residential roads will be plowed. It will depend on when a big enough storm comes into town.​ I guess this is what they are damaging, but I don't see how it makes any difference if it is 2" or 6". Damage the City budget, maybe... I attached the whole article in case it disappears on the other site.