Saying that agnostic has in practice become the true absence of religion (as opposed to atheism which is "supposed to be") is not a sensible statement. It's like saying that sometimes people dye their hair, so in practice blue eyed people are the true brunettes.
One thing that's interesting is that nobody sits around talking about the absence of things. It doesn't make sense to sit in a circle and talk about how there are no robot showbusinessmen on Uranus that are re-enacting Earth's transmissions and rebroadcasting them with Faster-Than-Light technology to their home galaxy. Likewise, atheists don't sit around and talk about how there's no god.
So if you see atheists talking on the Internet, or go to atheist forums, then it's almost by definition that they are talking about religions (usually the dominant religion in their area, which in English-language forums is usually Christianity). And just like most informal groups of people, some of them are total jackasses about it.
Even so, a statement like this seems starkly opposed to reality:
as a group they go out and try to force other to believe as they do.
I've seen an atheist argue that a condition of political office should be atheism, on the basis that admitting that you are influenced by things that aren't real means you are mentally incompetent in the worst way*, and I can see how that is like "forcing" others to believe as they do -- but this is not a common stance, even among the vitriolic internet atheists.
*I also know deeply religious people who got extremely uncomfortable with George Bush's "god talks to me" speech, because they might not agree with the atheist I just mentioned, but they follow his argument as far as thinking that it's really not a good sign if a powerful political leader claims to be hearing the voice of god in his head.