First off, we're slowly realizing Earth-like planets aren't nearly as rare as previously thought. Granted, we haven't found a place that harbors life as we know it, but we know the conditions exist somewhere "out there". In our solar system alone, we have both Titan and Mars, where the former might harbor life and the latter was probably Earth-like at some point in its past. Hell, even the Moon has frozen water. Then, we have all of those "Earth 2/3/4/5/6" we read about every so often in far off solar systems.
While various human civilizations have risen and fallen, the human race continues to thrive and become more technologically advanced, not as a matter of survival but because we choose to. Why would another species evolve in such a way that tools become necessary, possibly causing them to become more technologically advanced and intelligent as time goes by? The same reason we did, I guess. Or the same reason we're finding different species of primate using tools. It may just be a matter of course. Are we destined to destroy ourselves? While we tend to engage in self-destructive behavior, there's one thing we do better than any other species on this planet, and that's survive. If we have to live in a house made of ****, we'll do it. We don't know why, but that's not going to stop us from doing it.
Would our alien equivalent be as aggressive and violent as we are, or is that type of behavior specific to our stage of development or perhaps to our species, in general? Would a species similar to an insect hive destroy itself or work in unison towards a singular goal, thus increasing their efficiency as a civilization and species?
Should a space faring race exist, how difficult would it be to detect another race of beings that is purposely sending directed signals into various parts of space in an attempt to make first contact? Would such a race have the motivations as we do? Would it be easier to travel to the backwoods of the Milky Way to obtain various resources or mine the materials from asteroids and the like?
We should focus less on the answers and attempt to ask more questions. It's silly to attribute our characteristics to a species that in all probability evolved on a planet dissimilar to ours. Are they all peaceful and loving? Dunno, but would you really want to take the risk before we have the capability to defend ourselves from them should they turn out to be hostile? This is the kind of situation where it pays to be pessimistic.
On a side note, I don't see the point in pursuing ftl vessels when it'd be more efficient to fold space. Light speed really isn't all that fast when traveling in the vastness of space.
