I used to lane-split nearly every day when I lived in Southern California.
It was, and still is, the easiest way of getting around the bustling metropolis known as Los Angeles. Had I used a car, what took only a few minutes via motorcycle would've taken hours. How do I know? Because I'd done both and vowed never to brave LA traffic in a car ever again.
But throughout my time commuting to and from work, to events, and other places, I found myself confronted by car drivers who weren't happy I was able to bypass their eternal hell. I've been boxed in, pushed into the shoulder, literally pushed into another car, as well as hit by drivers who just couldn't handle lane-splitting motorcycles not having to deal with traffic like they had to.