US Corps buy all the coffee 3rd world countries won't drink. All the bitter nasty beans left by European, Asian and local buyers are scooped up cheap then blended with low altitude beans that have the taste but not the rich smoothness that altitude brings.
The end result is coffee that smells like Sumatran or Central American Highlands, but the bitterness is always there. Strong just makes it more bitter.
Take Kona, the majority of what you see is low and mid altitude for sale, then blended with a fine Columbian. The high altitude peaberry from that place is going to Ellison, Musk etc..they own Coffee plantations, Scallop fleets, Vineyards. You can't find that tangarine-sized Scallop in a grocery store, or those 5000 ft Kona peaberry beans. Them's all reserved, as the saying goes.