Yo be honest i can understand what Sawyer says but he is a kinda extremist on the balance factor. When pillars of eternity released the first time since Sawyer did not want any form of immunity in the game he did put only resistences in. As result you had hilarious situation such as. Oozes that can be blinded. Winged creatures slipping on Grease. It was madness and totally out of place and hilarious people went on and on in the forum to complain about this design decision Sawyer at the time was adamant to don't have immunities in the game till in the end he gave up and put immunities in the game.
He is a nice game designer but this is D&D and shaping the dice in that manner would be a total unnecessary alteration in the game.