[edited for clarity]
This is my new favorite conspiracy theory. Though in all honesty, and in spite of realizing the limitations in our ability to test such things, I've long considered the lack of accounting for life or life-like systems when attempting to formulate a coherent cosmology whatsoever to be kinda...naive? Short sighted? Not sure what the right word is, likely a combination of both and more.
The issue I take with it primarily has to do with social and more importantly scientific norms, I think. The vast majority of what most would consider credible scientists are, for example, pretty forthcoming about their belief in intelligent alien life existing, in spite of a complete and total lack of evidence for such a thing whatsoever (besides, ya know, us). But comparatively little attention is given to the notion that life could potentially have -- let alone if it already has had -- a profound effect on the cosmos. Especially since that might actually be something we could test, assuming the right people take it seriously enough for that kind of work to even get started.
If you think that extra-terrestial life is a possibility, and if you also think that same life could be intelligent, than you should probably assume there is life considerably and perhaps immeasurably more intelligent than we are (lest ye be accused of anthropentricism).
And if you think all of that is within the scope of reasonable speculation, then you should also probably humor the idea that the universe has already allowed for an almost comical amount of time for such life to evolve well beyond our own cognitive and technological capacity. Considering how much humanity has altered the universe in roughly 10,000 years (albeit limited to our own planet), to then disregard the potential influence an alien lifeform might have on a more cosmic scale if they got, oh, let's just say a 1,000,000 year* head start...well, like I said, it seems just a bit short sighted not to at least entertain these ideas.
If we're going to take the idea of non-Earth life seriously at all, then it probably wouldn't hurt to at least semi-seriously consider what advanced life might do and/or have already done in terms of altering the universe to better suit its ideal environment.
P.S.
Just wanted to let you know Sci, these threads you've been posting here semi-recently are ridiculously useful for me personally, and are really interesting just in general -- hopefully some day I will have the time to actually engage in some more genuine discourse on the topics!