I doubt its for exclusivity to the hard core. Normal mode was to teach people how to do Menagerie and possibly make friends to play hard mode with. LFG isnt needed if you play with your clan or friends. How many corrupted strikes have you done where people dont know to pass the ball between each other to power up the ball? How many blight public events or the frozen boss PE and people dont know how to make it heroic? You want to randomly match up with these people without good weapons and no communication to play endgame activities that send you to orbit when you all wipe? Bungie thinks this is a bad idea and i agree. I do secretly hope they do introduce it so i can read about all of the people complaining about crappy matchmaking because the idiots dont know mechanics and cant stay alive. One guy quit out and ruined our run! I doubt they would back fill a heroic game mode if people left, people hate it when they join a crucible/gambit game mid match.