Why would aliens want to destroy us?

If they are like us, why would they help?

Even if they don't help us, why would they harm us?

1. Graphene-based batteries (which are on the horizon) among other graphene products
2. Spacetravel outside of our solarsystem (Will not be possible within the next 50 years)
3. The establishment of colonies on Mars
4. Nuclear Fusion to solve the worlds energy problems once and for all
5. A games-console capable of holographic gaming!

These are not necessarily ranked in any particular order. Just 5 things I would like to see :)

Facism

It doesn't need to be them, though.

With so many violent (and religious) extremists around the world, I can't imagine the barbarities they would commit during their denial.

We can be talking like a tiny living organism on mars or something like that right?

Or are talking about actual intelligent beings from another planet.