The left lane, in most cases, is often described as a passing lane.
Sticking yourself in the left lane and refusing to budge is an invitation to danger.
Always use your turn signals.
Always look twice, three times before changing lanes.
Never tailgate.
Drive defensively.
Lead, follow or get out of the way.
All those rules make sense and everyone knows that.
Bad driving is like political correctness. 99% of the people dislike it, but its still there. Everybody does it.
Heck, I have complained about people riding my bumper WHILE I was riding someone elses bumper.