The LV-223 Needle in a Haystack

This is surely not a new thought but something that struck me as incredibly odd about Prometheus (although I love the film overall) is as follows: So they spend gobs of money to visit LV-223 & as far as I can tell, landed randomly at one single point of interest, thanks to bootleg Tom Hardy's 6th senses about God not building in straight lines, and yada yada. Now they proceed to inspect ONE structure, where they indeed find evidence of intelligence and ONE dead engineer (they did not see the corpse pile until later, right?). And here comes my problem: If they came to a planet (on an invitation) from our creators; would they not assume the planet is indeed their home? And like earth would have multiple spots of civilization, structures, or at least some intelligent life? (After all the captain later in the film says "this ain't there home" which means they assumed that initially) And you are telling me after only one day in one specific location they came upon [u]by chance[/u], they all deduce that perhaps all the engineers are dead & at one point Shaw even says "what killed them?" Which makes me wonder why they did not at least ponder the thought that there could be a plethora of life/structures ELSEWHERE on the planet. Because discovering one corpse in one building on an entire planet and thinking “they are all dead, mission failed, so sad” seems to me just like the famous comparison of scooping up an empty cup of water from the beach & concluding there is no fish in the sea. I know for theatrical purposes it was meant to be a big revelation when David knew about “many other” ships...but wouldn’t the entire crew assume that on this planet there must be other installations or intelligent life forms to discover? At one point I think Vickers even says “how much longer will this take” as if they came all that way to check one damn cave & go home with all the answers. Not to mention that if even one engineer was found & talked to, he could still simply be a grunt who doesn’t know shit. But overall it seems outright insane to think a trillion dollar voyage/crew would not have already assumed they would be searching out several locations on the planet for their answers (especially David or Wayland who only had a few days of life to spare). I may be too hard on this because it is after all fantasy, but the fact there was no crewmember who even brought up the idea that there were thousands of these structures or maybe cities elsewhere, blew me away.