You might say, "Oh well it's just common courtesy", but is it really? I mean if a stranger waved to you from across the street you wouldn't feel compelled to wave back to them. In fact you'd probably think they were weird. So why is it that in Destiny when we come across a stranger (exo or otherwise) in the wilderness that there is an expectation for them to return the gesture if you wave at them? [spoiler]But still, if you don't wave back at me on patrol I will hunt you down and kill your dog.[/spoiler]