The designer had performed research and learned that no, people DON'T care why they can't park, they just don't want a ticket; and that they don't care about fine distinctions, they want clear unambiguous information.
As for complaining that this misunderstands local government: that's the point, it's user-centric design. Parking signs should not be a catalog of the internal departmental divisions in city hall, they should clearly communicate to street users the way in which the street is permitted to be used. It's like complaining about the design of the iPhone on the basis that it completely failed to reflect the reality of how cellphone carriers operate. Yes, yes it did. That was the point.
That research is incorrect in my experience. People _do_ care why they can't park, because if the restriction is for street cleaning, and the street has already been cleaned, you can park (in my city). If the restriction is for construction, and work hasn't begun by 10am, you can park. So you do need to know _why_ you can't park, if you want to park in certain cases.
As for complaining that this misunderstands local government: that's the point, it's user-centric design. Parking signs should not be a catalog of the internal departmental divisions in city hall, they should clearly communicate to street users the way in which the street is permitted to be used. It's like complaining about the design of the iPhone on the basis that it completely failed to reflect the reality of how cellphone carriers operate. Yes, yes it did. That was the point.