In defence of the OP, notice that they did not talk about the original intent of clang, which is as you mention. They talk about the main reason of its corpora

In defence of the OP, notice that they did not talk about the original intent of clang, which is as you mention. They talk about the main reason of its corporate sponsors, which is an entirely different thing. It seems plausible to me that these sponsors may have different motivations than the creator of the project.