Pretty sure these all apply for Mars and Venus and they're dead planets. Not sure why everyone is assuming some exo-planet must have life when the two other examples we have don't.
I just feel everyone gets excited over nothing solely because its extra-solar. Our own solar system is fairly diverse. If life was common, we'd probably be seeing more of it here.
We'll have a better picture when we study our solar system in more detail. Maybe 100 years? I agree that speculation this early in the game isn't enough to get excited over.