I hesitate to disagree with anything in your detailed and thoughtful analysis, but - depending, of course, on who you mean by "anyone" - I think this is an unwarranted assumption to make.

I am regarded by my friends and colleagues as the most frequent flyer they know - largely because despite the fact that we are all professionals, none of us have jobs which require us to fly anywhere frequently or long-haul any more than very sporadically. Despite doing 2 runs to Oz/NZ and 3-4 trans-Atlantics a year, I only just qualified for QF Gold for the first time last year because of one crazy itinerary on a RTW, and will only requalify this year because of the lower renewal threshold.

QF Silver was still a real benefit to have. Priority check-in is probably the single most useful perk for a regular flyer unless you can online check-in and use automatic machines to pick up BPs at the airport. Lounge access comes second (often there is simply no time to use the lounge), and on QF at least can be bought for a reasonable price. Seating requests were almost always satisfied by QF and BA, with agents sometimes putting in quite a lot of effort. On QF and BA, priority boarding tends to secure you nothing except greater familiarity with your seat, neighbours and the faces of the pretty girls walking past to the back.

If your analysis is intended only to be relevant to road warriors, then it won't impact much on this segment of the market. But it's not right implicitly to denigrate QF Silver (or equivalent levels) as "unacceptable".