I am very gracious to my host and would never insult them or make it seems like I am ungrateful. The foods I dislike the most usually I have ways around it. I have mentioned more than once I dont really care for Gefilte, and I have a simple solution , its called Chrain, Just dump a ton of Charin on the Gefilte and I am good
Thnakfully the one I am really repulsed by (even the smell) is rarely served by anyone I know and if its done, Its only at Shala Shudos and never given to me on my plate. Its sometimes served at a KIddish in Shul and its almost never eaten except by one or 2 people and the rest is thrown out.
Like any other person there are foods you like and foods you dislike and some people dislike certain smells of things, Its not usually kosher , but I have walked past Indian restaurants (It might be the Cumin) for example where the smell goes into the street and couldnt wait to walk past that restaurant. But then again walking place some place of Bar B Q and that smell is amazing