Why would anyone spend an enormous amount of energy and time to reach us, a miniature rock that has nothing to offer to a space faring race?

Folks spend lifetimes thinking of philosophy or working on a single science problem. In addition, we are still exploring oceans, depths of volcanos, and we explore space as much as we can without actually travelling to the places ourselves. We research animals and our own bodies. Some folks spend a lifetime making music. Not all of these has a payback outside of satisfying curiosity or enjoyment, at least not upfront.

Considering this, why would it seem odd that a race would explore what there is to explore?