I'm loving how the Watermelons are showing up in force on a thread about a different planet.
"Humanity is a virus, we'd just destroy the planet, [insert hilariously simplisitic anti-human statement]," etc.
Let's have a little biology lesson real fast. Humans have issues, obviously. But to describe humans simply as destroyers is ludicrous. Fire ants and viruses have no capacity to create. Humans DO. Humans have the ability (even if a little late) to see that nature is worth preserving - I know a LOT of people who own quite a bit of land simply for the sake of owning land and enjoying it. That says nothing about the many parks preserved simply for enjoyment of nature. Then, of course, there's the ability to create - no other creature has anywhere near our creative capacity. We can harness the power of fire, rivers, the atom, and of the sun itself, to power vast cities, industries, and machines. We can fly higher than any bird, dive lower than any fish, and move faster than the swiftest creatures. Unlike viruses and fire ants, we have the capacity to appreciate beauty and feel compassion.
As for that planet, let's suppose we get there sometime, it's suitable for human habitation, and it has sentient life. Now, there are two likely scenarios - that life is far behind us in tech (stone age) or is vastly ahead of us. In the former scenario, there would be few enough that we could colonize the planet without the locals ever finding us for a few hundred years - there'd be no reason to exterminate them. In the latter, they would be able to easily keep us from landing if they wished.
Now, the most likely scenario? It's a barren chunk of rock with no life whatsoever. May or may not be suitable for terraforming. If there were no life, but life could be added, there would be room only for creation, not ruining it. How, precisely, does one go about "ruining" a lifeless chunk of rock? That's like ruining a desert - it doesn't make any sense.
