We have been inhabitants of Earth for a long time
and we are still discovering life we didn’t know
existed. Let’s not rush things.
Are you kidding? This planet is about to explode, and I'd rather be somewhere else when that happens. Not wishing ill on the potential Martian bacteria, but when it comes to the well being of my family vs them, them bacteria are toast.
Seriously, we need to get sustainable human presence elsewhere, and apart from the ideas i've seen for colonizing Venus (Floating cities! Yipeee!) Mars is the only other potentially viable game in town.