I should have made it more clear that I was using "pro-atheist" in the sense of the organized atheist movement. And yes obviously that movement is ideological. Worse for quality of thinking, it is political, in the sense that it has some clearly defined political allies (and also enemies).

I think it's indicative of some deep biases that this stuff, unlike ideological rants in general, can be posted on LW with general approval

Remember it wasn't posted separately, just as a batch of stuff from Skepticon. I doubt that many people from LW have seen it.

But yes some blatantly ideological material gets a free pass or at least much less scrutiny than is warranted (such threads show up in discussion once every week or two) because of the demographics of Lesswrong. Like any group of people we bring our politics with us at least implicitly (even if it is explicitly banished), which translates into ideological sympathies and the vocabulary of applause lights we use and recognize.

In addition most users here have a warm fuzzy feeling when they hear atheism, which might mean they misidentify to which contrarian cluster someone actually belongs to.