Or you just have the genes for a stronger bitter taste, and it overwhelms absolutely everything else.
I can taste PTC paper from across the room. It's horrible; painful on the tongue to actually try one.
That said, crank up the cocoa level on my chocolate to 95%, so long as it's the good stuff. But forget black dark roast coffee, bitter beer, or raw greens. Painful, more like the bite of capsaicin than a flavor. My guess is there's some difference in the bitter compounds among the four; there are several bitter genes and they react differently to different compounds, so all this stuff tastes different to each of us, and it's not just an all or nothing sort of thing. You're lucky in a way; chances are you aren't actually tasting as much bitter as some of the rest of us do. No big deal, so long as there are options for everyone