The most straightforward answer is that if we did everything differently on Earth (love one another instead of fighting), we’d be creating instead of sowing the seeds of our destruction. If we wouldn’t have wasted time building missiles? May have already been to our sister planets by now. All of the rocket and propulsion science from 1947 onwards would have been focused on interstellar and intergalactic travels by now, true to the words of a well-known scientist who once gave a lecture regarding aliens.
What if they’ve visited us before and consider Earth to be a second home, thinking of us as their cousins? You can bet they’ll return once they see we can all get along. But right now, we don’t, and many don’t seem to care at all about our beautiful blue planet. Of course, if anyone is out there, they’re keeping themselves well-hidden. As an author, I like to think that we can all get together to work towards changing the future for the better, and I truly think of myself as a futurist.