Tyson said roughly, as I quoted, that philosophers are just wannabe scientists. That's wrong, so Tyson doesn't know what philosophy is.
The hybrid science-philosophy thesis is Tyson's, and I was accepting it for the sake of argument, but also because the gist of it, at least, is undeniable. The point isn't that all premodern Western thinkers were equal parts philosopher and scientist. Rather, the point is that the boundaries were blurred, so lots of thinkers found themselves doing what we'd later call separate jobs. Aristotle's a good example.
The reason it's worth criticizing scientism is that when scientists like Tyson condescend to philosophers, they're not treated like just some blokes on the street. They leverage their authority as scientists to pontificate philosophically while simultaneously dismissing philosophy.
But mainly I wrote more about this when I discovered, to my surprise, as I said, that Tyson may have replied specifically to me (and to other bloggers from 2014).