Bitterness does taste good to some people. Dark chocolate is way more interesting than milk. The peel of a charred lemon wheel on some broiled fish is bracing but brings incredibly complex wood and floral notes.

I actually agree that most coffee tastes pretty bad and is drunk as a drug not a beverage. That’s why I take mine with too much cream and sugar usually. But if you like tannins and you get someone who knows how to bring them out coffee can taste good on its own. I’ve tasted it done right but never managed to do it myself.