I have a partial answer to the question expressed by the author of the letter "Chronic left-lane drivers should move out of way."
I believe few drivers today have taken a driver's education class in which they would have learned the rule: Stay right unless to pass.
The reason for the rule is safety. Our vehicles are designed with left-side steering rather than right-side as in England and many other countries. Left-side steering safely allows a motorist in the right lane to more easily see motorists in the left lane when there is need to pass a vehicle in the right lane or when a left lane exit is required.
Motorists who are addicted to the left lane obstruct right lane vehicles' access, thereby increasing the probability of an accident. Also, this addiction affects vehicles merging from the left even when the right lane is unoccupied. We should remember that it is difficult for a driver to see across the passenger area for an opportunity to merge with left-lane traffic.
As for those motorists who have learned this rule but do not obey it, I can only speculate on their failure to do so.