It was very anthropocentric for earlier humans to believe that they were the center of everything, but it seems to me equally narrow-minded to suggest that we have the one (and only) winning lottery ticket, which is a fundamental basis for the multiverse theory.
Sure...the evolution of our *exact* manifestation of life may be very specific (= improbable), but the evolution of some sort of life may not be so rare in very-large-scale dynamic systems. And I certainly don't believe that we understand the basis of consciousness well enough to say what kind of organization / order might give rise to it, so who's to say that only one of the lottery tickets is a winner? Maybe they all are!
We're finding evidence for potentially life-sustaining environments elsewhere in our galaxy (i.e., practically next door), so maybe self-aware life is a lot more common than we think, and if we're open-minded about what life is (and acknowledge that our limited senses might not even be able to perceive it all), maybe there's a heck of a lot more of it around than we think.
And if so, then what's the justification / need for the multiverse?
(If what I wrote doesn't make convince you, don't worry...one of the other infinite me's in the multiverse wrote a lucid and compelling version of this post, so just pretend that you read that one.)