My peer group makes a difference too, of course - 20s, educated (many in science), urban. Rural areas are less atheist-friendly, like in the states. Still, I can't really imagine a conversation like that happening with our PM. The "one nation under god" thing isn't really a thing here. No prayer in public schools, no creationism in public schools, gay marriage has been legal for nearly a decade with no signs of society collapsing, etc.
We also tend to be less extreme in our identification with groups in general, for whatever reason - e.g. many people change their votes from left-wing to right-wing between elections, because there aren't really massive differences between them, and we don't tend to personally identify with our political party as much. So that probably contributes to less "militant" views as well.
...Crap, I shouldn't be in this thread, should I. Oh well, I'm not the only non-American here.