It's just not an issue though if you're splitting in very slow\stopped traffic, which is really the only time you should be splitting. There's nowhere for cars to move to or reason for them to move over. Yes, youtube videos of bikes doing 120 through stopped traffic make it seem really dangerous and stupid, and yes, doing it that way is really dangerous and stupid. If practiced within reason though, it's just not an issue and it works so well for getting around in congestion. At a societal level, it improves congestion and reduces motorcycle fatalities. What's not to like about that?