There's no way for me to prove something that hasn't happened yet, it is purely conjecture. However, I'm basing it on a couple of simple ideas. Most of our universe is empty space. We are so incredibly far away from everything else that even if there is other life out there, it will be a good long while before we find it or they find us. On top of these vast distances, the odds of life actually getting a kickstart on any given planet are so astronomically low that, combined with the fact that we are so far from everything, any other life we find likely will not have found any other life itself, before us.

But that is deviating from the main point. You asserted that any life that is more intelligent than us would be uninterested in us, and I find that idea to be absurd. Look how excited we are about finding other types of life here on our own planet. We could find single-celled organisms on some other planet and I guarantee we would study them to no end. Just because we are more intelligent does not mean there is nothing to learn from them.