What was the guy going to do? Stay? Trump has made it clear that he doesn't want to stay in Syria longer. Others do. Like Mattis and this guy.
So, are you for longer drawn out conflicts such as Syria? If not, would you not agree with "cheeto"? So, if you agree with "cheeto" then you would agree that he doesn't need a special envoy to fight ISIS in Syria.
You coach ball. That would be like a head coach that runs a west coast offense keeping a staff full of guys that know the wishbone.