Unless maybe you are losing a war, being chased relentlessly across the stars and need to make a bomb shelter under a thousand miles of rock. You could offer the natives all sorts of technology, or all the precious metals you find in exchange for a few cubic kilometers deep under ground. Whatever deals you make with them don't matter anyway. They'll all be glassed in a few years when your pursuers figure out where you're hiding and begin bombardment.

Or imagine making peace with the aliens, what will they think of our nearly endless collections of movies, video games and stories wherein we're slaughtering, mutilating and murdering or visitors from the sky? I wonder how _that_ is going to look once they understand what they're seeing.

Highly doubtful. Any trait that's collectively exhibited was adaptive and such a spefies would value it to some extent, so they wouldn't breed it out entirely. If some new sub-species found a better way and outcompeted those with this trait, then they are already better adapted by definition, and so wouldn't need this trait.

To study us. Intelligent life, and maybe even complex animal life, may be incredibly rare in the universe even if life is common. It may even be so rare that even an aggressively expansionist species might choose not to colonize our system because of the value that might be associated with a natural experiment such as ourselves.

So assuming expansionism, the question is, can such a species survive long enough to be a threat to us? If their societt is unstable, they may well destroy themselves before getting very far. Stability seems out of the question here - that would imply they are able to maintain a steady-state society within limits, but still have the need or impulse to hunt for new resources and living space.

So maybe we're not likely to meet such a species as it is likely to be self-destructive. One configuration is worrying, though: An expansionist species sufficiently advanced to reliably spread across space without end, but still bound to eventually exhaust any resources they find. (Inevitable for all species given entropy?)

This species will either die out or monopolize all resources it can find. (And then die out.)If it really requires constant growth, it can do nothing else.