I imagine what’s happening is that the signal of bitterness overrides any other tastes and flavors. Sort of like trying to listen for whispers in the midst of a concert.
I enjoy coffee for example and savor it like wine at times; chewing and getting the aroma into my nostrils.
However it took a very long time for me to get used to and ignore the bitter and toasted flavors to even notice the complex flavors in a cup of quality black coffee.
I don't know if I'm a supertaster though, I've always thought my sense of smell and taste to be below average.