YEC was originally primarily an American thing, and moreover, a political movement far more than a religious one. It was designed specifically to circumvent America’s strict separation of church and state laws, by a bunch of people who envisioned an American theocracy, of course with themselves as “theo.”
As for atheism, while there is nothing inherently fundamentalist about it, I do perceive in many atheists a sense of absolute conviction and intolerance that I do not share. I truly, honestly do not know whether there are any deities, and have no particular gut feel on the issue either (and as Carl Sagan said, I prefer not to think with my gut.
It is possible that some of the fundamentalism we see today is indeed a reaction to militant atheism, but who can tell?
Personally, I think non-religious people should spend less time arguing with religious folks about whether gods exist, and more to simply argue for proper separation of church and state.
I have also begun to think that churches are not necessarily a bad idea, and that many of them carry the seeds of their own eventual destruction inside them. The Catholic church was the first such institution: during medieval times, it actually played an important role in keeping learning alive and creating some stability in a very dangerous and chaotic world. But combine learning with stability, and you almost automatically create a more educated populace that will eventually become more skeptical of church authority.
I think many churches today are going the same route. Even the more fundamentalist ones are not opposed to learning per se: my experience with fundies is that very often they are actually very literate and well read, and they live in communities that are often quite peaceful and stable, indeed more so than the gangland that surrounds us. And by this, they are once again creating precisely the conditions that will lead to their own demise.
Perhaps churches are a natural part of the evolution of a more secular society.
Either way, I simply cannot find the passion in me to endlessly argue with these folks. I call it “having a life.”