Listen I’m not sure how much experience you have with these knives. But we’re talking brands like Shun, MAC, and Tojiro all of which harden past sixty and many more. Like I said I have a Shun. While its very hard and that’s responsible for some of its issues (it chips easily) it is not really any more difficult to get an edge on there than my softer European knives. And the edge isn’t particularly long lived as goes the comparison either. It can take slightly more effort to grind out chips but putting an edge on there is no different really than anything else. I believe the knife was sold (discontinued model) as being 62 or 63 Rockwell. Straight razors are commonly cited to have a rockwell range of 55-65+. And I’ve seen old straight razors from very well regarded makes shatter like glass, even though they were able to take a crazy good edge relatively easily.
Some of the knives I’ve worked with that are the hardest to remove metal from are cheap no brand stainless knives with a pretty low Rockwell. More contributes to how tough it is to sharpen a knife, how hard it is to remove metal from it, and how long lived the edge, than just rockwell score. Its sounds like your applying the common complaints about older (and current low quality stainless steel) to any steel with a high hardness rating, perhaps all stainless steel knives.
