I take this as another sign favoring transcension over expansion, and also weird-universes.
The standard dev model is expansion - habitable planets lead to life leads to intelligence leads to tech civs which then expand outward.
If the standard model was correct, barring any wierd late filter, then the first civ to form in each galaxy would colonize the rest and thus preclude other civs from forming.
Given that the strong mediocrity principle holds - habitable planets are the norm, life is probably the norm, enormous expected number of bio worlds, etc, if the standard model is correct than most observers will find themselves on an unusually early planet - because the elder civs prevent late civs from forming.
But that isn't the case, so that model is wrong. In general it looks like a filter is hard to support, given how strongly all the evidence has lined up for mediocrity, and the inherent complexity penalty.
Transcension remains as a viable alternative. Instead of expanding outward, each civ progresses to a tech singularity and implodes inward, perhaps by creating new baby universes, and perhaps using that to alter the distribution over the multiverse, and thus gaining the ability to effectively alter physics (as current models of baby universe creation suggest the parent universe has some programming level control over the physics of the seed). This would allow exponential growth to continue, which is enormously better than expansion which only provides polynomial growth. So everyone does this if it's possible. Furthermore, if it's possible anywhere in the multiverse, then those pockets expand faster, and thus they was and will dominate everywhere. So if that's true the multiverse has/will be edited/restructured/shaped by (tiny, compressed, cold, invisible) gods.
Barring transcension wierdness, another possibility is that the multiverse is somehow anthropic tuned for about 1 civ per galaxy, and galaxy size is cotuned for this, as it provides a nice sized niche for evolution, similar to the effect of continents/island distributions on the earth scale. Of course, this still requires a filter, which has a high complexity penalty.
What you are saying doesn't follow from the premises, and is about as accurate as me saying that magic exists and Harry Potter casts a spell on too-advanced civilisations.
After a 6+ month hiatus driven by grad school and personal projects, I am finally able to continue my sequence on astrobiology. I was flabbergasted by the positive response my last post got, and despite my status as a biologist with a hobby rather than an astronomer I decided to take a more rigorously mathematical approach to figuring out our biosphere's position in space and time rather than talking in generalizations and impressions.
Post is here: http://thegreatatuin.blogspot.com/2016/03/space-and-time-revisited.html. Seeing as this post is an elaboration on the last one, I am posting a link rather than reproducing the text.
To summarize, I found some actual rigorous observational fits to the star formation rate in the universe over time and projected them into the future. These fits show the Sun as forming after 79% of all stars that will ever exist, and that 90% of all stars that will ever exist already exist. This makes sense in the light of recent work on 'galaxy quenching' - a process by which galaxies more or less completely shut off star formation through a number of processes - indicating that the majority of gas in the universe probably won't form stars if trends that have held for most of the history of the universe continue to hold. It relies heavily on analysis I began in comments on this site a few months ago.
I then lift two distinct metallicity normalizations from a paper that was making the rounds here a while back ("On The History and Future of Cosmic Planet Formation"), in an attempt to deal with the fact that that is a measurement of STAR formation, not terrestrial-planet-with-a-biosphere formation. Depending on which metallicity normalization you use (and how willing you are to take a couple naive assumptions I make in order to slot the math that is too complicated for me to comment on on top of my star formation numbers) the Earth shows up as forming after either 72% or 51% of all terrestrial planets.
These numbers are remarkable in how boring they are. We find ourselves in an utterly typical position in planet-order, even if I am wrong by quite a bit. We are not early. Of interest to many here, explanations of the so called Fermi paradox must go elsewhere, into the genesis of intelligent systems being exceedingly rare or the genesis of intelligent systems not implying interstellar spread.
Now that I seem to have a life again, I will be getting back to my original plan next, talking about our own solar system.