Playing Alone (Destiny)
I mean LITERALLY alone.
I believe I've tracked down the cause, but have no way to prove if I'm right or not. Earlier this week I managed to hit Queen's Favor Level 1. With this I obtained a shader and the Queen's Guard emblem. I put either, or both, on and I have the entire playfield to myself.
As in "There's nobody else here but us game AI."
I wonder if it's because I haven't gotten around to meeting the Queen yet.