That being the case, why does he feel the need to serve as some sort of ethicist? Why do ethics exist at all? On what grounds does one defend the ludicrous idea that matter in motion has ethics?
All of our moral confusion has one source: the rejection of Theonomic positivism and the search for a more general, "universal" ground for morality based on "natural law," "right reason," "common sense," etc. Not that these things don't exist, but they also get all their validity from G-d and without Him would not exist.
And it's not just liberalism that's the problem. Chrstianity's rejection of the Torah and the American Founding's rejection of objective religious truth (which we all know as "religious liberty") are also very much implicated and paved the way for later liberalism.