There's an interesting corollary here. Atheists aren't necessarily trying to win converts. That's largely a pointless exercise. People come to accept atheism based on their own knowledge, experiences, and analysis. An atheist will never come to your house, interrupt your dinner, and tell you how wrong you are and how there's A Better Way. You can't say the same about many religious people, who can't wait to "witness" to you, invite you to their church, and persuade you about "the good news" they're dying to share.

Atheists don't come into schools to try to subvert (not convert) children in the way that many Christian organizations do. Atheists don't put up signs in classrooms denouncing the existence of god, yet Christians can't wait to have the 10 Commandments and "In God We Trust" all over classrooms and other public spaces. Atheists don't strive to remove books from libraries or to narrow what students are taught.

Regardless of which community is "right," which one is more offensive? Easy answer.