If the majority of your community already is white, doesn't that satisfy whatever urge that is? Why would there be a further need, if there are many white people in your community already, to have an exclusively white space, unless you are a racist? The point of POC communities is to connect with people who face the same struggles in society as a racial minority, so would the point of a group formed by a white majority be to unite under the shared "oppression" of a majority?