If it’s sitting out buffet style, yeah…I’m skipping that, because self-serve buffet means to help yourself to whatever you like.
But if you invited me for supper, and we sat down, and you put a steak, some cauliflower gratin, and one of those potatoes on my plate, I’d be obliged to eat it, and compliment you on it. To do otherwise would be considered horrendously and unforgivably rude on my part.
That’s just how my mom raised me. Never, ever under any circumstances, say anything negative to somebody about something of theirs (food they made, clothes they’re wearing, etc) to their face. You do the polite thing and say how nice it is and then trash it in the car on the way home. That’s those Southern US manners we were taught.
I can’t remember who it was, but I really want to say Rick Bayless in an interview, said much the same thing, that you should eat anything offered you as a guest, unless it’s a question of health, like an allergy. If it won’t kill you, smile, eat it, say “How nice!” and move on, because food is love and when you reject someone’s food because “Ick, I don’t like that!” you’re rejecting their offer of love and friendship.