All good points, really, the majority of drivers in the US are utter ****e, no doubt.
Been startled myself being caught off guard by an R1 passing at extreme speeds.
None of that changes that prudent splitting is safer for a biker than plodding along behind a car. When stuck in traffic constrained by an arbitrary law you become a victim to circumstance and cannot self determine. When you have the option of passing an erratic/drunk/new/horrible/etc driver you control your own environment.
We all know bikes vanish to car drivers, they just don't see you. I myself have come up on the back of a car only to realize there's a motorcycle sitting there I didn't see, usually because he's in the one or three position in the lane and the tail lights line up. If I can make that mistake as a highly competent driver/rider then ANY random cager can and will make the same error.
You be you and I'll be me, regardless I'm still splitting when prudent and safe, tickets be ****ed!!
EDIT: I'm not talking about splitting two cars going 65mph at 150mph plus! Yes it's fun, yes it's unfathomably dangerous.