I don't understand how people are worried in either direction.
This primitive species that we are, can't do shit about it anyway so why worry?
They come here to kill us. Okay, can't change their mind.
They come here to be friendly. Okay, can't stop them.
It's just a boring rock? Either it hit us or misses us. Either way, I can't change it so why waste energy on something that is out of your reach?