This problem isn't just with destiny, it's a massive epidemic since games have gone towards ranking based on how often and much you play. Ranking are no longer based on wins, losses, and skill. Therefore people don't care to communicate, they don't have to communicate and play better to level up, they can just get away with playing. In H2 and H3 the ranking structure was set up in a competitive way and it forced communication so that it was possible to win, and if you lost you would lose your rank. Until they bring back that type of a ranking structure nothing will change in communication, no one will use mics, and people will continue to play alone because they can and still get xp... A competitive ranking structure based on skill and winning will fix the issue, I would knots guarantee it, no one wants or likes losing their ranking and if it meant they had to talk to win, they would....