The point is that if previously they had, say, 85 people with 30 working on organized car theft rings and 55 on random single thefts; then a reasonable result of a tenfold decrease in random thefts would NOT be 80 people on organized car theft rings and 5 on random single thefts but instead 40 on the organized crime (if it has increased), 5 on the random thefts, and 40 people moved away from the car crime, either to something different within the police or laid off to make budget for other useful things such as medicine or public transportation.
Demand for various niches of gov't service will change, that's a given. When it's not enough, bad stuff is visible, voters complain and service gets increased. What happens when the demand falls, as it has in this case? We need an ability to reduce the size as well.
The grandparent's comment has merit. Government has stayed exactly the same size.