So do I.
If Earth had something of critical value to some space-faring race, and they were here, we'd already be enslaved and working in their mines and factories.
We're not, so why are they here? To study primitive humanoids? I think they would have made all the observations they needed and would have departed long ago, if it was simply curiosity.
A culture that has the ability to move through the cosmos at faster than light speed would probably find little value in our little mud ball of a planet. They wouldn't bother going to the hassle of overcoming the natives to get after some valuable mineral or such, when they could easily get the same thing from some planet without intelligent life.
No - they're most likely monitoring this place as a potential source of contamination to the "neighborhood".
I fear they plan to tear it down to make room for an intergalactic bypass.