Yes I saw this too while playing the Beta
I saw this but it doesn't matter much to me
So playing Destiny Beta, I was creamed by the enemies and it was very reassuring to see them use cover fire and surround me. But whenever I walked up on a group, or I came up behind them, they seemed the be literally apart of the landscape; they just kind of stood there waiting for someone to walk right friggin in front if them. Maybe Destiny could put in some patrolling mechanics for enemies so they don't seem so bland at first. Don't get me wrong, playing some levels on hard was aggravating, but just maybe at some life to them? Even have them chilling around a campfire (if that's what aliens do) playing some weird alien game or have some of the lower level fallen be skittish if their comrades die. Even when I was scoped in down my sniper in the open world, a group of fallen would just be zoning out, you could easily have a enemy look out with a pair of funky binoculars scouting around. Please fix!
This was one of my worries pre-beta, that the AI would just wait to be attacked in small units. I agree that their use of cover and evasion was nice, that raised my hopes for clever AI, but the lack of patrols quickly reignited my disappointment. The first time I went into explore mode, I quickly learnt enemy locations and how best to avoid them - that should not be the case. With random patrols, a hierarchy system that makes smaller units flee and other random things that make enemies feel like a threat rather than sitting ducks would be terrific. I was about to critique MMOs for having packs of enemies clustered in the same spot, but then I realised that most of the time they're placed willy nilly and move about a bit. Giving mobs schedules, responding to the chain of command and perhaps even in-fighting would make them a lot more interesting. ^^