Humans possess "bitter" taste buds for one reason and one reason only: to detect poisonous compounds. If a primitive man popped a berry into his mouth and found it to be bitter, he knew not to eat that kind of berry anymore.
We are literally biologically programmed to find coffee unpleasant. This isn't my subjective opinion. It is objective truth. It isn't possible to truly "like" coffee any more than you could like any other noxious stimulus like being burned or cut. Basic neurology tells us this.