> If you want higher detail location information, do what Google did and send out cars with sensors.

It's not just about the locations, but about the interactions between the rider(s), driver, the location, and the time. A location might be difficult to pull over at during rush hour, but nearly empty later on. Drivers might be unable to get very close to an event venue. Certain streets might be difficult to drop passengers off safely on, based on traffic conditions (though we wouldn't know that). And of course, there are many applications around customer support that couldn't be solved otherwise.