I dunno, it seems to me that a lot of Gem tech is gem activated [i]only[/i], plus while they got hella science they also have a bunch of magic going on as well. Unless humanity finds a way to data mine Gem computers I don't think they'd get much out of the actual stuff that was left laying around. Besides weapons, don't see why humanity didn't find all of this Gem weapons and be like, [i]"Hey, let's turn this impossibly sharp weapons into bullets to fend off the Monsters that show up to wreck our families every once and awhile."[/i]