But it isn't racist to say that here in the USA we have an American culture as well as an American citizenship, some people have one or the other, or both. The USA does have a culture (for good and bad) just like other nations.
Chelimo is welcome here and I am a fan. He is an American citizen. But he hasn't lived and grown up in our culture of high school sports, food, television, video games, cars, or mixed-phenotype melting-pot ancestry, etc.
The things that make it hard (or easy) to be an American runner were not the same for him as they were for millions of American kids on various HS track and cross-country teams.
That is why he doesn't feel American despite having the paperwork and dedication to become an American. Respect to him for that, by the way. But he is not going to eclipse Shorter, Prefontaine, Ryan Hall, Galen Rupp, or Bob Kennedy as our best long distance guy.
p.s I have a good friend from Senegal who is legally, and thus technically, French. He would be shocked if you called him French. That is, to him, obviously nuts. He has French citizenship but is Senegalese, obviously.