Upon reading the Coin Collector's Survival Guide, I learned that there was a similar problem with ANACS grading at one time. I believe this was the "old ANACS."
They used a technical, or academic, grading scale to describe level of preservation. They attributed problems with the coin separately. If those problems were not the result of wear/preservation, they did not detract from the technical grade. But this readily leads to a VF without problems being valued higher than an AU with problems.
What most collectors seemed to want is a market-based scale. This would require a net grade be assigned that would take into account more than just the technical level of preservation--the extraordinary weak strike of which you speak seems to fit in this category. This net, or market-based, system would allow a pricing structure whereby a VF is worth less than an AU, which is worth less than an MS.
I'm not sure how all this has shaken out in the
TPG area, but it seems to remain a problem. Though the unsympathetic are apt to say, "buy the coin and not the holder," or "a slab is no substitute for an education," I think the hobby will most certainly contract if people get burned in large numbers by nuances in the
TPG philosophy.
Personally, I wouldn't mind if MS-60 and maybe MS-61 were permitted to catch specimens with no wear, but diminished detail; with MS-62, one would have the expectation of seeing all the intended details. Under such an arrangement, the price range of low MS coins would overlap with AU coins and maybe EF too. Would this cause confusion? Maybe a bit. But who hasn't seen a choice AU specimen adjacent to an unappealing and lower-priced MS-60?