I hate wasting anything - money especially. Why would I throw money at something I don't need when I can put that money towards something I'd rather have more? If I am not driving the car for 4-5 months out of the year, why would I continue to pay for collision and liability coverage that applies only when the car is being driven? If someone wrecks into my house, my insurance will cover the damages and subrogate the party at fault. If my house collapses onto my car or a tree crushes it while it's parked, it's covered under the remaining comprehensive coverage. "Less coverage" implies bad - in this case "suitable coverage" is more accurate.
I pay my premiums in a big lump sum every year, not monthly. So it's an immediate chunk of change that gets returned to me when I suspend the driving coverages.
Anecdotally, if you owned a boat, would you continue to pay for insurance that would cover its sinking, if you were storing it on land for an extended period of time?