No it is not crap. We do buy wines that give different profiles as they age, but in very old age, there are plenty of instances where it is very difficult to tell different regions apart.
Ian - not in my experience. I have to disagree with you entirely.
I’ve done many blind tastings where we compared one region to another after 30, 40 years or more and the wines from different grapes/regions do not converge. In fact, they can be much harder to distinguish in youth than with some age.
Why? I don’t know exactly.
I think it is because young fruit can seem mostly like well, young fruit, but with age, the various compounds within the grapes and the wine combine and recombine and evolve and become something very unique. You started with different raw materials so you end up with a different product.
I can promise you that Tempranillo from Rioja does not age like Nebbiolo from Piedmont or Merlot from Bordeaux or Zinfandel from Santa Cruz or Pinot Noir from Burgundy or Syrah from Australia or the North Rhone.
Many years ago I began collecting Spanish wines because in doing comparative tastings of wines with age, I consistently found that if there was a Tempranillo-based wine, I preferred it. I figured I could keep them 30, 40, 50 years or until I wasn’t around any longer to enjoy them, and other than Nebbiolo-based wines, I wasn’t aware of another grape that produced wines that lived as long.
If today you taste a group of wines side by side from the 1940s, 50s, 60s and 70s, from different regions, as long as they still have life, they are not converging.
Otherwise why not go out and buy a few cases of some good Zin and keep it until it turns into old Margaux? I drank a 1992 Zin last night. It wasn’t anything like any Bordeaux I’ve ever had. And my Gigondas isn’t going to turn into DRC in the next few decades.
Once you get past the point where there is any flavor at all left and it’s little more than colored water, I guess they converge. But not at some point where you still want to drink them.