*snips rest of post, however, it is a good argument, that I can't think of anything to add to it or counter it as it stands right now*
I'll adress this point below, by which I mean throw out a point to consider. It doesn't mean however that I think your point hasn't merit, it does. I guess I'm just trying to play Devil's Advocate here.
Milky Way has been having the ability to nurture life for ~6 BILLION YEARS. We're the first species to develop intelligence/civilization/technology? Why is intelligent life so scarce?
I did previously mention that there is the possibility that life, especially intelligent, may not be evenly spread throughout the universe. There's nothing in evolution stating that a civilization building type intelligent species is a definite avenue of evolution, so even if life is spread evenly, highly socially and technologically advanced species may not be a very guarantee at all wherever life appears.
It may be possible that humans are in the galaxy with among the lowest concentrations of life in the universe. There are countless galaxies in the universe, and it wouldn't surprise me if there were some places that were nearly barren even at large areas.
I know that my argument is really just arguing from probability and statistical ideas, but the possibility can't be discounted. Hopefully its not a complete load of rambling.