It's the one I take when a longer blade is necessary.
As for needing a better steel, it's common as blade lengths go up, alloys go down. Two factors - cost and fabrication of a tougher, harder to work blade starts driving expense up, it seems adding one more inch makes the blade twice as expensive. It certainly takes longer to shape, and a flaw late in finishing loses more in work in progress expense.
Second, bigger blades don't necessarily warrant a harder to sharpen blade. They get a lot more chopping, and rougher cuts on larger media. Fine work that needs a thin scapel like precision cut isn't their forte. The type steel should have more shock resistance for getting beat on, not a high hardness thin edge that is more likely to chip than roll over. Sharpening it back shouldn't take a benchtop diamond stone, either - it's a field knife, and may likely only see a medium grit rod to touch up for the weeks duty.
If Spyderco did go that route, I would expect American manufacture, an S30V blade, and about $120 - not the affordable monster I have. I've got a S30V knife already - and it's a royal pain to get back to an edge, something to schedule for a long snowy Sunday afternoon, not a quick touchup. That's the plus for the Resilience, it's a user that maintains easily and carries better than a fixed blade in a sheath.