Precisely and I know everyone has forgotten the concept of gravity wells* because Star Wars and other scifi shows constantly shows spaceships constantly flying up and down from planets like it is no big deal*... but ALL of those resources are stuck in the bottom of a gravity well which means the value of a bulk amount of any of that material is far less valuable than it would be distributed in space in other forms that could be mined without paying an immense energy tax (asteroids and smaller rock bodies than "planets" in general, i.e. why mine an earthlike planet when you could mine a pluto like planet or smaller?).

Sure, maybe aliens have Stargates or some other magic teleporting/portal device where they can appear magically on the surface of the earth and then warp back to somewhere outside the gravity well of Earth.. anything is possible I suppose but if we can't assume that nature doesn't allow such a blatant paradox/violations of the conservation of energy than we can't really have any speculative discussion about anything since it might just be superceded by magic at a later point.

The most valuable thing to an alien sentient species capable of such immense power would unquestionably be the genetic diversity of all living species on earth and that really would be the only scenario I could conceive of where aliens might desire to destroy humanity, I could see them having some kind of gardening philosophy where they could see we were a threat to the biological diversity of a potential ongoing source of genetic innovation and wanted to protect that by eliminating us... but even that is a stretch... from the timescale of an interstellar voyager, mass extinctions are simply the closing of one act and the beginning of another in the story of evolution, the evolution of life on Earth in all its complexity cannot be understood without taking into account mass extinctions... so then what would make an alien species decide to see the mass extinction that humanity is precipitating as fundamentally different?

Of course it is possible that an alien invasion force could show up and blow us up with lasers to harvest all our coal.. but I think there are basic axiomatic assumptions people bring to the table about assumed ways that alien contact would bear out that are just downright silly and I will not stop making fun of them until this genre of conversation becomes more mature.

All good points. I don't see why that means they wouldn't come and exploit our resources too. Maybe after they used up the other planets. Maybe they just like destroying things. People like to imagine aliens as moved past all the petty shit that holds humans back, but the ship of the aliens that we meet might just be "rich kids on vacation and want to shoot an elephant" type of aliens.