I think we should move the discussion off from the main thread, but I don't think of Grana Padano as a better or faster Parmigiano Reggiano, it is just a slightly different product. Like aged wine or whiskey, (somewhat) different notes for different tastes and occasions.
An important bit is also the quality control of the process for these protected products. Some, such as dietary requirements for the animals, or cumbersome, long winded processes can have more or less subtle effects on quality. Many optimized methods can get close (e.g. by adding the major components affecting flavour), but there is often something missing in depth.
Also I feel that because industrial production is so much more efficient, they scavenge off a lot of (unprotected) mid-class products. Regional products can still be great, but it is often hard to find them in grocery stores (and then they tend to be similarly expensive as European imports).
What I found especially in the USA is that folks are so used to these products (e.g. American "cheese") and oversweetening of products that often many standard (and usually cheap) products such as sausages contain ungodly amount of sugars and fillers, whereas the actual meat remains on the bland side.
I know it sounds snobbish (though someone with Italian heritage should be used to that) but the mass produced foods seem to twist the taste of folks toward sweet, overflavoured products. There are in fact studies about this phenomenon (mostly in the US) and while origin production might not be the best solution, it is a way to incentivize the maintenance of more convoluted, but ultimately less overproduced food.