James I am glad you brought up competition cutters, I had forgot about how they could fit into this discussion.
They're very specialized blades, and I probably wouldn't grind or HT a general purpose camp knife quite the same way. But much like race cars, pushing them to their limits does offer insights that can carry over even to a mundane sedan. (I credit my friend Ken for pointing out the race car analogy to me; he often refers to his comp blades as "race knives".)
PD1 is interesting stuff. I haven't even studied it much less worked with it, but I hear cool things about it.
He used some of the "old" knife steels very successfully.
True, but it's important to remember that in his time he was widely criticized for using "new fangled" steels like 440C and 154CM, being a pioneer in using high-alloy steels and thin grinds, and even - GASP! - not forging his blades, but grinding them out of barstock. The tired old arguments about stock-removal vs. forging, in terms of blade performance, have very much faded away in recent years... but there are still a few places where you can find yourself in a knock-down drag-out fight for even bringing it up.
Long before the end of his life, Loveless had fully embraced powder metallurgy. I don't think he's a good example of someone sticking with "old" steels. Quite the opposite, in fact.
440C and 154CM are still as good as they were back then - except for the unfortunate fact that the quality of the steels themselves has fallen off badly (poor mixing, poor cleanliness, etc). But if you like them, you're going to love CPM-154, Elmax, etc... they're simply better across the board.
When we consider how/why these alloys are actually developed, we're not talking about fast food or disposable razors or even pocket knives, where companies mostly just re-arrange the same ingredients to have an excuse to make a glitzy new commercial or magazine ad. The mills have to be able to show industrial users that buy steel for dies, slitters etc by the ton that the extra expense really pays off in longer tool life.
It's not a matter of replacing "old" steels just to have something new to market, but of learning from them and improving upon them.
It just so happens that many of these new alloys also make truly excellent pocket knives and fixed blades, but we are a mere drop in the bucket of their demand.