I mean, there's a ton of resources floating around in space, so, if anything, it's the whole invading/visiting/whatever Earth for resources that doesn't make any sense. Unless those resources are humans, then yeah, those are harder to find elsewhere.
On topic: Aliens, confirming that intelligent life exists out there and has been here would be awesome. Hell, it could be that they come here for fun/entertainment or some other triivial thing, sure, a lot of people say that it wouldn't make sense to travel that far just for that, but that's because of how hard it is for us to imagine travelling such distances, could be that for more advanced life-forms jumping from one planet to another is no different than going from one country to another is for us earthlings. I don't know, I just watched GotG Vol. 2, so all kinds of crazy space travel ideas are in my head right now.