From that article you linked: “Some of the worst abuse could be outside the Capitol and around public agency buildings throughout the city.”
This actually makes sense. State buildings and court-houses rarely have adequate parking near by. Since they are usually downtown, the only places to park are street parking and the government garages. Few of those buildings have more than 1 or 2 handicapped designated spaces on the street. Those garages can be close, but rarely are. They are usually at least a few blocks away, which is kinda far for someone who has trouble walking for whatever reason. That means all the people who work in those buildings who have a disability, have to park on the street. Thus, the high percentage of cars with placards near places like that.