Of the ex pilots I have worked with, not many have made good ATC’s.
Of those not so good, it's been obvious their thought processes have been along different paths to those of the better career controllers.
That appears to be the case in the proposals/scenarios put forward by pilots in this thread. Pilots supposing how controllers should act is just an example of how wrong their concept is of the ATC game.
Controllers dread the thought of being involved in the unthinkable incident. They know that no matter what airspace rules are in place, the various legal personnel will find a way to attribute some blame to ATC.
This is why low level E airspace is an anathema to controllers. Controlling IFR’s and having unnotified VFR’s in the same airspace, just does not make sense to them.
As Albizia pointed out, Tower can provide much more efficient control than Centre, because the separation standards available in Tower airspace are considerably less restrictive than in Centre airspace. I don’t think our thread instigator realizes this.
I also think that one man's VMC is the others IMC. It's all very well to say CAVOK, but in between that and IMC, there are a myriad of conditions that make "see and avoid" questionable.
CG