We have seen, in talking about blends, how there are excellent single-quality coffees, but we have also seen how it is difficult to have them in large quantities for mass marketing, a fact for which the blends offered by various roasters have since arisen.
Consuming coffee from single pure qualities is a bit like going back to the origins of coffee consumption: in fact, not only in the past centuries, but up to fifty years ago the majority of families roasted coffee at home, buying it raw in the grocery store, where coffee from one bag at a time was usually offered...and logically all of the same quality.
Then this habit, in Italy, disappeared in 1966 with the famous "anti-smuggling law" that introduced the loading and unloading register of goods, thus suddenly making all small dealers/retailers of raw coffee disappear.