I agree that there is a lot of silence in group content in this game, but my own experience isn't nearly as bad as it seems to have been for you. For my own part, I always try to advance what I consider as good gaming culture, as in greeting people I'm grouping with, encouraging and giving advice when asked etc. Not that I'm anywhere near perfect, and I don't always have the energy to be very active socially. But I think the best thing you can do is, be the change you want to see. Maybe with your good example you can inspire others to act the same way.