Our world is based on 2dimensional, heaven and hell, good and bad, devil and god,etc. Our morality is based on this also. Lot of our sanity is anchored in belief in the creator who is fantastically omnipotent, omniscient and omnipresent. This has kept in line and is the bedrock of our society.
Aliens with superior intelligence,etc are very unsettling for us. If aliens are as superior as we know them to be, they will probably treat us as the amazon tribes and let us be with our limited intelligence,limitations. Possibly they are our creators,us being some chemical equations and laboratory experiment for their greater,superior intelligence.Superior as they may be, aliens would be with faults, angers,etc...very much like us. In a manner of speaking subjective and prone to errors. They live, they die...like this case notes had happened. they may be superior but in a linear development path from us.
The above equation means that if the full alien knowledge is unleashed on to us, our world morality and value system will be shattered. We will perhaps not believe in our fallible gods any more. There will be no more compunctions to act on, we would be rudderless. How wonderful! This takes us back to the collapse of the USSR, it happened and we were ok. Why does the aliens unleash their superior knowledge onto us?
Perhaps their superior knowledge has some think to do with their reticence?