Bad coffee beans if not roasted to charcoal state taste even worse. Argument that that most of available coffee in VN is made from pretty bad beans, so roasters have no other way to roast it to that level.
That's it.
But a dark roast is easier to produce, and easier to produce consistently. If you take high quality beans, and low quality beans, and roast them both to a dark level (let's say "French" or "Italian" roast), they're going to taste approximately the same. Therefore if you're producing coffee at a larger scale and want to save money, you can use cheaper beans and roast them dark to mask the imperfections that come with the cheaper beans.
There are some truly incredible coffees out there and a well-executed light or light-medium roast will bring out those flavors beautifully, but the quality starts at the coffee farm. You can't light roast a low quality coffee bean and expect those same excellent flavors.
Also: What do you say about Italians drinking a cappuccino or macchiato (expresso shot with a splash of steamed milk)? From what I have seen while traveling in Italy, most Italians drink coffee at small coffee shops. Or French people drinking cafe latte?
However, roasting coffee dark does homogenize the flavor of the coffee, and you do lose more and more of what that coffee tastes like. Coffees have a ton of different flavor compounds, and no two coffees are the same. There are quality issues and processing issues though that don't help to highlight this too, so it's hard to find coffee - even from people who know how to roast - that can shine in this way.
I think everyone should try a good coffee that has some punchy flavors - I'm not saying everyone should like it. It's a fun thing and should be experienced if you're interested.
Side note:
I rarely drank coffee (or tea, although I do drink tea again, somewhat, nowadays).
I used to drink Indian-style milk tea almost daily, earlier, in school, college, and later.
So once, some years ago, when I walked into a Cafe Coffee Day [1] shop (an Indian coffee shop chain, possibly modeled on Starbucks), and after looking at the menu, ordered a macchiato. it was a pleasant surprise to find that it tasted very good. :)
(I had nothing against coffee, it was a common drink at home, growing up, the filter coffee [2] kind, but also Nescafe and Bru, just that I did not prefer it much, later.)
[1] https://en.m.wikipedia.org/wiki/Caf%C3%A9_Coffee_Day
[2] https://en.m.wikipedia.org/wiki/Indian_filter_coffee
Filter coffee has kind of cult status in some states of South India.
Applies to vegetables and other vegetarian foods, too :)
Ever tried eating raw wheat, rice, pulses or vegetables? Only some vegetables are okay in salads.
also french coffee is horrible mostly because it is controlled by only one group in a mafia like fashion where they rent you the coffee machine but you have to buy their beans. italians can make good coffee with old espresso machines and average beans which says more about their skills than anything else.
If you are in the last box, you cannot get to the first one, but you can still move one step up by burning it. Plus you can add a lot of milk and cream and then it is almost the same anyway.
Overcooking and adding a lot of spices makes everything (more or less) edible. With less cooking and less spices, you can better taste the original ingredients.
I'm sure you will agree that raw beef and a steak taste differently?
Meanwhile, people that don't mind "burnt coffee" are the people that preferred coffee-based drinks from coffee shops. If I get a salted caramel mocha Frappuccino with two pumps of hazelnut - burnt beans are probably the only kind of beans I will be able to taste in that drink.
good one, bro.
now, walk the plank.
https://en.m.wikipedia.org/wiki/Walking_the_plank
I'm sending you to Davy Jones' locker.
https://en.m.wikipedia.org/wiki/Davy_Jones%27s_locker
:)
jk
I am not a expert on the science of cooking, these are just my casual, slightly scientific observations as a layman :)