It gets a little better, though -- any species with resources to cross interstellar distances probably has better things to do than gratuitously turn a small-but-biologically active planet into (yet another) molten hellworld.
If the aliens are stopping by to refuel, they'll probably head to Jupiter or some other larger planet with more raw materials.
If they're here as scientists, collectors, or tourists, they'll probably want to leave Earth more or less as it is (modulo some sample collecting), since it wouldn't make much sense to destroy the things they came to look at.
If they're here for the delicious human-steaks they heard about on the Intergalactic Home Shopping Channel, they're doing it wrong -- rather than traveling light years to round people up, it's much quicker and cheaper to just download the recipe and assemble the ideal human-steak locally in their in-home matter assemblers.
If they're here for other inscrutable alien reasons, they may not bother with Earth at all, or even notice that there is anything unusual or interesting about it.