The issue here is if they break it on the job, they get replaced on the company dime. Isn't much if it's a $500 beater, but if it is like my truck, it's more than any smart car. And this doesn't include any other damages incurred. Then there is the modifications required to perform that job. There was a forum I came across some time ago for LEO's that used POV's on the job, was interesting to read through, but every time one got wrecked, it didn't even go on their (the individuals) insurance, it went to the state. Even if it was off duty.
Perhaps things have changed a bit in the last few years, and I know it will be different from state to state. For me, when standing watch, I have used my own POV on occasion instead of the provided when I felt my 4x4 was safer than the 2wd death trap van we were provided with, but I have been told that if I had an accident doing that, my INS wouldn't cover it as it was on duty, and the Navy wouldn't cover it ether, and I would have to pay all expenses out of pocket.
I do agree with you, but I have an experience that leads me to disagree with you. I have worked outdoors at a place where we were repairing a water main on the property in the middle of winter with no way to warm up. I had an 86 ford escort, I parked it next to the hole and we would take turns going from wet hole in the ground to warm up in the car. I don't think I should have had to provide my own car for that, and that job could have been dangerous with out it.