Bungie has given the answer of design choice and adding more meaning to infusion. Whether or not people buy that is up to them, but that's bungies reasoning behind their change. In terms of individual players, no one can give a valid reason as to why it cost even more shards, glimmer and planetary mats. So i really dont see how anyone not part of the dev team can validate having it. Then again the question itself is what benefit do we have for cost of infusion itself altogether? Cost of anything really. Added hurdle to do multiple things in the game. Personally i don't care if it stays or goes. As for the nerfs, those were warranted and better reason than enhancement cores. People may not have liked the changes but made sense nonetheless.