good point.
what makes you think i do or don't believe anything in particular and/or that i'm not just playing around with various concepts? is "rational" better than "irrational?"
rationality has many flaws, particularly when fetishized and full of latent value judgments... and in fact such uses are quite self-contradictory and pretty funny most of the time...
and "realistic," well, is full of potential sillyness too, particularly in the context of what is mythical.
the "foundational flaw" is speaking or writing in ways that either directly claim or suggest that rationality, science, facts, or knowledge have any bearing on faith. they don't. on the flip side someone is trying to find flaws in a survey design to counter the idea that those of faith don't know much, when it really doesn't mater if they know much or not. the entire thing is moot. i find athiests who are wrapped up in trying to "prove" that religion is silly to be very entertaining. they often shove their beliefs, shrouded as non-beliefs but fully vested in the (irrational) faith of rationality, down others' throats just as vigorously as any overly-avid christian.