Think about it, everything in Evangelion could have been prevented if Yui Hadn't been such a pretentious -blam!-wit. Because of her stupid god complex the world was destroyed and everyone died even Adam and Lilith. She could have prevented all of the confusion and emotional pain if only she just let someome know what she was planning from the begining. Gendo probably wouldn't have abandoned Shinji the way he did, and thus shinji wouldnt have been such a terrible pilot and could have actualy been alot more efficient at defeating the angels. (I mean look what happened when Asuka realized that her mother's soul was in Unit 02) Yui could have even helped, We know her soul could communitcate with Shinji at will so why did she? With Shinji's mind syched with the Eva, Yui would have known his pain and given him some encouragement. Just her presence would have been a huge boost to his morale, but no she just had to -blam!- with his and everyone else's lives and emotion's and she only decided to help when her own life was truly on the line...some mom, and people call Gendo a bad parent And let's not forget about Yui's "genius" plan to use an untested procedure based on the intentional missuse of the most powerfull and bareley understood possibly sentient extraterrestrial life-forms bowing to the whim of an emotionless teenage girl and the cooperation of the most emotionally fragile child on the face of the earth to trap the soul's of all of humanity inside of a crude and poorly understood Proto-Type bioweapon, and launch it into space to drift aimlessly and inactive after having destroyed your own most powerfull weapon in the hope that none of the other indefinite number life forms in the universe that poses the exact same ultimate weapon have figured out how to preform such a mundane task as throwing a spear. And this does not account for the endless obsticles in space including Radiation, Stars, Black holes and meteorites just to name a few. And all of this is assuming that this fragile bio-weapon is even capable of surviving in space at all to begin with.