Experienced players don't have any interest in welcoming newcomers to raids anymore. In the earlier days of Destiny it was easy; if you'd played the other, previous raids, there was ample support available from the commmunity that would welcome you. Now, due to Bungie's more recent, segregated thinking with ROI's release, if you don't know anybody you play alongside regularly, no veteran wants to stick their neck out. It's even worse finding teams using LFG... In a lot of ways, Bungie has alienated newcomers with veterans.