Influenced by Hitchhiker's Guide to the Galaxy
The aliens were quite complexed with us. Yes, they understood sex and biology, but they were quite disgusted with the dating game. They could not believe that we still used currency in the color green. Money was obviously supposed to be yellow, to imitate GOLD.
I get bored easily. I can go on, but it's me, me, me.
The aliens were also exhausted at obvserving how selfish we are.
The aliens got sick of us in 1 sec, because there were more places to go. But they knew we would be a buzzkill to their friends, so they made abolutely sure to never allow us to ever leave our planet. So, here we are, not even knowing of our disgrace, funnily.