I agree up to a point. Once your "take the lane position" has slowed a car to match your speed, the needed safety margin for a pass is actually very small. So there's no risk to moving over when the way ahead is clear enough (ie. not at a sharp curve, or near the crest of a hill) to allow a pass even at a close distance. Of course this is a judgement call, but common courtesy demands that you respect the motorists legitimate desire to proceed, to the same extent that you want him to respect your rights to the road.

I routinely ride to the right of center of the lane (or right lane) but move over promptly once the car has slowed to a safe passing speed, unless specific conditions warrant that I hold him back a bit longer. The last thing I want behind me is a frustrated, impatient person who'll seize the first opportunity to gun it and race past without regard to conditions. I try to avoid that with a mental countdown timer started the moment a car drops to my speed.