Tinting, as befits the subject, is not a black and white issue. Opinions come in different shades.
Some drivers appreciate the privacy that heavily tinted windows grant them and in a hot climate a degree of tint can keep the vehicle cooler. But nonetheless, the police are right to clamp down on heavily tinted windows.
One issue is paramount: safety. Obviously the driver of a heavily tinted vehicle has limited vision at night and even during the daylight hours their ability to view the road is diminished.
Speeding compounds the problem and while fast driving contributes to the vast majority of accidents, shaded windows serve only to aggravate the situation. It is far safer for all road users if drivers can see and be seen. Any vehicle, at whatever speed, has the potential to cause injury or worse. Transparency in all walks of life is usually a good thing, especially on the roads.