Ask any "East Indian" what their population and subgroups actually consist of and you will get an immediate list of subgroups, immigration history and ideologic

Ask any "East Indian" what their population and subgroups actually consist of and you will get an immediate list of subgroups, immigration history and ideological differences. You're right that those are all equally social constructs. Same with Arabs, that's a massive group. When someone is discriminated against with a broad brush their list of qualifications for "an ally" is often the other people equally maligned in that group, so if "Arabs" as a group talk back to discrimination against "Arabs" then that's an unsurprising development.