Aww. Poor grapefruit. According to xkcd ("A webcomic of romance, sarcasm, math and language"), the grapefruit is the single most difficult, untasty fruit around (see above diagram, charmingly entitled "Fuck Grapefruit"). Amazingly, it's been deemed only slightly less difficult to eat than pomegranate, which is really saying something because eating pomegranate is a truly Sisyphean torture.
I would propose that anyone who says the grapefruit doesn't taste good should head over to Range in the Mission, find a nice seat at the bar and order the cocktail known as the "Vin de Pamplemousse," which I can say with confidence is the best fruity cocktail I've ever had -- and the principal mixer is grapefruit. It also has Square One Vodka, Viognier, vanilla bean and lemon. Check it out, grapefruit haters. (via Serious Eats)