So many people have this wierd notion that Earth is some kind of rarity in our Universe. But that just doesn't make sense, statistically or realistically.
I find the evidence of everything on Earth to indicate that it is quite unique, although by no means am I trying to disrespect what you think.
Virtually everybody in scientific communities make a very stark leap in saying, "well, if prerequisite A, B, and C are met on a planet, then the planet will almost CERTAINLY have life." Having a planet in the habitable zone of a star by no means make it have life in the first place. It has to have so many things going for it, it's a statistical impossibility for life to occur without an intelligent force behind it. You could say, "if it has the right materials, temperatures, gravity, and protection needed for life, then it almost CERTAINLY have some of it's own." That's like telling me, "well, this would-be skyscraper has all the right materials here, and there's even enough rivets to hold the metal I-beams together. Oh, and look, there's plumbing and electrical wires over there ready to be installed. It MUST be able to create itself." But if there are no workers to put the skyscraper together, what exactly are you saying? That the skyscraper WILL put itself together? Go ahead and say that to a stranger, and they'll laugh at you. But that's what people are saying about life, and it's virtually overlooked.
Now, that's not to say I wouldn't want to see another planet like our own though. But you have to step back and look at all the assumptions you are putting in place.