He's referring to demos that have been around for years and I've been following the space, too. His argument doesn't really refute any of my points. Knowing how the rasterizers work is never going to hurt you, quite the opposite. If you're serious about computer graphics you'll really want to have internalized both raytracing basics and rasterization basics. If I didn't know how triangle meshes are fed into the GPU and processed until the "final fully lit&shaded output pixel" for any one of my 94 favourite games, I'd feel pretty uneasy. Rasterization will always be orders of magnitude faster by necessity: that means when raytracing can finally render ca. 2004 scene complexity (think GTA:SA -- hint, it still can't even at quarter-res), rasterization can render ca. 2016 (or 2018 or whenever) scene complexity at full-res. Guess what the folks at Rockstar, Ubisoft, Crytek wanna do? Throw more details, more content variation, more procedurally-generated or -perturbed geometry at the screen at 60+ FPS. Sure Brigade can reach almost/barely 30FPS at some low resolution in a small limited preprocessed scene and then there's no more room for any physics, any AI, any animated crowds etc etc at all. They're doing important work and one day the big payoff will come, but for the next 10 years knowing how our rasterizers works will not be wasted at all.