I dont know what kind of HDR you refer to. My point was that for realistc rendering or physically based, whatever you might call it, a linear workflow (light calc in linearized space) is crucial. It is very important for the artist too if you aim at realism. Of course it brings challenged such as exposure correction and managing dyamics. These challenges are not yet fully solved but to say we ought to abandon HDR and go back to SRGB is at least questionable... we might as well go back to mode 13.