First let me start off by saying this is a neat little known combo that many are afraid to talk about because Bungie might hotfix it. BUT in reality I don't think it's really something that can be abused in many scenarios. Maybe your opinion is different if so please comment! There is a way you can still gain the benefits of the Touch of Malice double damage without the penalties of losing your health. The Sealed Ahamkara Grasps have a perk where melee has a chance to reload your primary weapon. When that unique perk procs you now have a fully loaded Touch of Malice that is shooting at the double damage perk without the penalty of losing health. The melee procs around 50% or so and throwing knives also can trigger. Not a huge thing to exploit really cause what are the places this would be advantageous? I'm not gonna try to melee things in a nightfall or raid to manage my ammo. BUT it's just a cool combo that I'm sure is already on Bungie's Radar. And doubt it's that important to even fix.
PvP exploitation will see this nerfed. Like procing ashes to asset on a corpse for a free golden gun.