This is my experience too - I'm limited to not being able to run Nightfall and Raids (or challenge of the elders) because i dont have enough Destiny players in my frends list. I would love to experience VOG and all the raid dungeons because that whole part of the game is closed to me. Im sure i could join a clan or find people in Destinylfg but that has never been an efficient solution and as others have stated it can take a long time to organise, time i dont have usually.