It's not so much whether someone has hit anyone - speeding laws exist for a good reason to protect other drivers, pedestrians, cyclists, etc. There's a good reason that school zones are 25 mph for survivability in the case of a car hitting a pedestrian (especially for small children).

There's certainly issues with speeding laws and enforcement, but at the end of the day the US is so car-centric that removing someone's license for dangerous driving can severely impact their ability to get to work, etc.