The usual (atheistic) defence against the Anthropic Principle is to take refuge in the tired Star-Trek trope of there being quadrillions of parallel Universes, one of which is ours.
It's not atheistic, it's common sense because it may very well be true. Outside creator, and multiverse are BOTH explainations that fit our observations of this universe. Either could be true and there is nothing to indicate one is more certain than the other. So you can't write off one as "tired" and "unscientific" without doing so to the other.
Hold on there pard. There are some folks who hold quantum interference as prima facie evidence of a multiverse - it is the different universes interacting. And then there's the proposed test (by Deutsch I think) of using a quantum computer to test the multiverse. IIRC, he proposes a quantum computer programmed to solve a yes/no problem. If the computer tells you it defintely determined the answer but can't say what it was, then half of the computation was done in a different universe.
For my part both are too tenuous to be convincing.