I hear you, and long term it's a pretty good idea (if we don't blow ourselves up first, which it isn't clear that we won't). I just hope they wait until we know more about Mars before contaminating it too much with Earthly microbes and waste.
It's true, that we could be the only technological species, at least in the galaxy. It's not much of a leap to think that. We'll never know either way unless we meet another civilization. But all the more reason to not blow ourselves up if we are it. How much more petty would our skirmishes with each other be if we are alone? Too bad more people don't appreciate things like that.