@DevilsbestfriendisLunar Talk to him and tell him that he is fundamentally wrong about his DMing skills. A DM is a force of nature not the frikking predator.
And yapp, I know that type of DM. In my experience those are often very resistant to reason and have not single bit of a feeling about proper game design. And yea that's very important imo. Tell him, that he should take a pause from DMing and just play the game and experience it from the player perspective. I suspect that he doesn't even know how a good game looks like. Sorry, for the ranty aftertaste but DMs that think it's their job …