For the same reason that humans have not "made contact" with ants.
Why do you assume a higher intelligence would even be capable of making contact with us on a level we understand? The discussion would be meaningless, in the same way that an ant would not comprehend our desire to build a freeway right next to their ant hill.
We have "made contact" with pretty much every species that display even a little intelligence though, including ants. Ants just don't notice when they run inside some scientist's experiment. Do you propose that we're so drastically inferior that we don't even know someone is having us find the cheese in a maze?
Yes, I think this is literally true. Messages may be encoded in the arrangement of stars, via PCM-neutrinos, etc., and humanity would be ignorant.
The history of biology is discovering species in places previously thought unlivable: impossibly salty environments, volcanic vents, etc. A natural extension is finding species in places "above" humanity.
An ant cannot "see" not comprehend the purpose of a freeway, no matter how hard we might try to explain it. It would walk right over it and not think it were any different than your average rock.
Sure, but that doesn't change the fact that the ant's ant hill gets destroyed if the freeway is built over it. Or that the ant itself gets crushed if it gets run over while walking across the freeway. The ant will notice those things even if it doesn't understand what caused them.
Exactly. Thus far, all we can say for sure is that we have not yet been carelessly crushed to make room for some intergalactic freeway we do not understand.
That doesn't mean there isn't one right in front of our eyes though.
For the same reason that humans have not "made contact" with ants.
Why do you assume a higher intelligence would even be capable of making contact with us on a level we understand? The discussion would be meaningless, in the same way that an ant would not comprehend our desire to build a freeway right next to their ant hill.