LOL.
I totally agree - talk about something people either love or hate - GRAPEFRUIT
I have a theory (no scientific support) that the bitter flavour in Grapefruit is like phenylthiourea in that I think some people can taste it and some people can't.
For those of you who forget grade 9 science class - that was the little paper strips that you lick and about half the class tastes nothing and the other half tastes pure unadulterated evil. It's a genetic thing - you can either taste it (me) or you are can't (lucky).
There's something similar with cilantro. I read this article that links it to genetics. I personally love it and can't have enough of it. My wife hurls just thinking about it... So I named my band after it