Apparently, the call for more realistic gore in the John Wick universe came from the fact that David Leitch and Chad Stahelski, both trained stuntmen who worked on The Matrix with Keanu Reeves, are versed in how things like gunshot wounds, snapped limbs and other sorts of grotesqueries look in the practical world.
So rather than ramp things up Tarantino style, the call was made early on to keep it real, straight on through to John Wick: Chapter 3 – Parabellum.