I think he's missing Hume's point... Morality has a motivational influence that reason alone lacks. If you think that it's "objectively" better to cure the pandemic than count blades of grass, then that value itself is rooted in something that makes you feel better about yourself, which is something that can't be attributed to reason alone. It's not just "objectively" true that counting blades of grass is stupid and curing the pandemic is worthwhile, it's our feelings on the matter that makes it better or worse. And if you're feelings are that counting blades of grass is morally better than curing diseases, who are you to call it stupid? Talk about elitist...