Perhaps my three best gyutos are Shigefusa, Kato & Devin Thomas. I do not know the steel of any of these. I bought them because of reputation and recommendations. Not knowing the steel didn't affect my ability to learn how they perform and sharpen and my own experience has backed up that information.
To Jon's point of dealing with what the customer needs rather than what type of steel they want and the car analogy: Do you really need to know if a car has 4, 6 or 8 cylinders, or do you need to know how much power it has, it's efficiency/gas mileage and it's reliability? If Jon were selling used cars and I went in and I said I want a V8, I might miss out on 6 cylinder that has comparable power, less weight, better efficiency, etc. Preconceived notions aren't always a good thing.