Black coffee made from instant coffee is understandably horrifying and tastes like ammonia smells, but have you considered fresh coffee? I don't mean filter coffee, either, the filter paper absorbs all of the tasty coffee oils, leaving only an ashy aftertaste, I'm talking espresso, moka pot, greek / turkish coffee and french press.
Similarly, if you normally find that you hate dark chocolate, perhaps it is because your chocolate is made with slave labour and also not very good.
I am currently enjoying a fine ten year old aged Java. It is very tasty, and I highly recommend.
I used to drink coffee black all the time because I had Kona coffee and it's great
Also you probably think you have had Kona coffee but you probably haven't. They put 10% of the cheapest Kona beans in with whatever and just call it Kona coffee. That is ALL KONA COFFEE sold outside of Hawaii, unless it specifically says 100% on it.
This coffee does not have some particular flavor, it's literally just very smooth coffee.
Say Kona is half as bitter as another coffee- that would mean you'd be dropping the bitterness of that random ass coffee by a whole 5%. You could do that just by using a slightly less shitty coffee for the base. So it's literally nothing. There's literally no relationship between the tase of a 10% Kona blend and the taste of Kona coffee.