I can't really add much more than what others have said, but I do think there IS a premium market for pipe smokers. But it isn't in the tobacco, but in the pipes themselves. That is where serious money is laid down; where there are objective standards to measure quality; where there is a sense of collectability and permanence; where there are artisans that are highly respected and live on the reputation of their craft alone. Those all seem like the kind of elements one would need to buttress a "premium" or, perhaps better stated, luxury market.
If I'm understanding Cosmic correctly, the real thing you are driving at is:
1. Why isn't there something equivalent to the sommelier in pipe tobacco consumer culture and marketing? Cigars have something similar, more or less, as do many other categories of food and drink consumer goods. So, why doesn't pipe tobacco have anything similar in its own consumer culture?
2. If such a thing did exist, would that mean more robust and "natural" tasting tobaccos with fewer artificial additives, beyond the obvious and necessary additives to make pipe tobacco safe, palatable, etc.?
If I understand that all correctly, I would say it is because the pipe tobacco market is still too small and niche. To try to carve out a small and exclusive niche in an already niche market that already costs considerable amounts of money and time, may be too daunting for would-be entrepreneurs to pursue.