It certainly contributes towards avoiding the proverbial "let's kill it! ... whatever it is." mindset. Your example of orcs is an apt one. And not to get too far off the track, but, I sometimes had a problem with a lack of explanation regarding what it is that was gnawing at the orcish psychology. You just had to accept that they were the bad guys (things), and, as you say, were there to be killed. In a Traveller setting we, as players and referees, would probably be asked to examine the orc issues; i.e. is there a lack of farmland, something in their water that's making them irritable, or perhaps they're just naturally aggressive and need some form of social structure to keep them pacified.
Sci-fi, unlike fantasy, asks us to examine our actions when confronted with the strange or unknown. I guess when I brought in the whole "monster" theme I actually was thinking in terms of space clouds, amoebas, giant robot planet killers and so forth, but as many a poster here has reminded us, that doesn't necessarily have to be the case. The monster, whatever it is, is more or less a phenomenon that the players don't regularly encounter readily in a Travellerish setting.
I guess that goes without saying, and perhaps I'm just showing off my ability to extrapolate arguments here, but a monster, however large or small, may not be a "monster" as such. It may not be misunderstood, heck it may not even be intelligent, but perhaps a thing or sorts that poses a unique opportunity for the players to address a problem posed by an entity that is unaware or simply doesn't care how its actions effect other life forms. And perhaps that's the key to good "monster story" material for any story or any kind.
I like that. Thanks jawillroy.