I think you misunderstood me a little. I went into my mod work with my 700's already ripping the switch out because I'm going to keep it in DC mode and any superfluous (again, only to me alone knowing what I am going to do with it) circuitry like the switch would be bypassed - my own "purist" approach on a unit that was mine to work on and I listen to daily. The switch was gone even before completing the build and testing it. I had hum and ground issues even with it out of the circuit, for which both grounding analysis AND taking into account the level controls (again, make sure they are NOT wired with the wiper adjusting the input side) was how it was overcome. Now the "3rd extreme" is to bypass the level controls altogether, but even I haven't been quite sold on that concept.. but that to me is also an option - to discuss and not assume, if you catch my drift.
If I was working on a unit from another owner, and they specified the switch to stay in and function as it should, well there wouldn't be any argument past one quick "Are you sure?" question, explaining the pro's and con's. After all, it's not my amp to make that decision.