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I'm not sure the lack of "real time" communication with an extraterrestrial civilization would be as disappointing as suggested. I suspect it would have the same characteristic in tone as some of our more revelational archeological discoveries about past civilizations, only with far greater impact. Remember how people lost their minds for years after the Tutenkamen discoveries? And we had known somewhat about ancient Egyptian culture already beforehand. 

The rare resource here relates to organic materials. Trees? Can't find those in space. Plants? Of course not. Of course, any advanced lifeforms seeking out those resources would know that destruction or conquest would make them non-replenishing commodities.