


It's a mixed bag, there are dozens of ways to brew coffee, and then throw in thousands of different bean combinations, and roasts. I don't see how one method could be superior knowing all that. You can easily spend months trying different coffee beans, and everyone is going to have a slightly different opinion on what tastes right to them. It's very autistic to spend a couple years trying beans, because you can't waste the bag, and then trying different brewing methods for each bean, and then trying another bean a month later, rinse repeat until you find the one.
Usually black coffee "lovers" are recent converts, they always want you to drink it black too. "oh, just try it for a while don't worry you're gonna love it! It just took me a while to get USED to it." They have converted to black coffee, because they didn't realize 8 cups a day with milk and sugar has a caloric impact, and they are fat, but still need to fuel their caffeine addiction, or some other health related reason. Who am I to burst their bubble.
I think having other flavors in the cup, be it condensed milk, regular milk, or whatever make sense if they enhance/balance the bean out. Whatever the beans the Vietnamese use, they seem very dark, but the condensed milk lifts them up a bit and makes a nice drink on ice. Or maybe try a really light roast, use more beans/water ratio than a medium/dark roast, then add a little foamed milk and a couple drops of honey. In good food achieving that right balance of sweet/salty/bitter/sour in the right amounts is what makes it good. It's like you're telling me to grill my steak with no salt or anything, that doesn't make sense to me. Black coffee makes sense if I'm having some kind of brunch with rich/sweet foods, then it's a nice contrast to my meal. If I'm just having one cup, relaxing, give me foamed whole milk, and a hint of honey/sugar.
TL;DR coffee is autistic, and the addictive quality of caffeine biases peoples taste buds.