What I claim in this particular example is that, since the secularization of progressivism/liberalism around the Enlightenment - and its pragmatist/utilitarian posturing - it has been having trouble deriving moral equality from first principles here, and deep down there's awareness of that. So liberals desperately try to derive an egalitarian "ought" from an inconvenient "is" - even though nobody's forcing them to!

This seems like an ok model to describe what his happening.