Ophelia Benson says this well.
Here’s what I do say: I say 1) I want atheism to be an available option for people who want it, and 2) I want people to abandon the expectation that religious claims will be treated with automatic deference … I want, in that sense, to put religious people on the defensive. That’s aggressive, if you like.
The only people I know who are even slightly interested in converting people to atheism have an accomodationist stance. All the aggressive atheists I know agree with Ophelia.
I don’t want people to abandon their faith because I really just don’t care what people believe. At all. Be as wrong as you like. Really, it’s fine. Don’t imagine that I won’t tell you why you’re wrong, because it’s fun, but I’m not interested in converting you. I just don’t care about you or what you think and you won’t change your mind anyway. It’s not worth my time.
It’s only when you start telling me that I have to believe stupid things too that you’ll get my attention. It’s only when you gang up with a bunch of your creepy friends to complain when I laugh at your foolishness or try to pass laws saying I can’t or try to teach schoolkids that evolution isn’t true or discriminate against or otherwise harm women or homosexuals or institutionalise and cover up widespread child abuse or demand special privileges for members of your group or that privileges be taken away from everyone else or tell me I am necessarily morally bankrupt and therefore evil because I don’t believe your particular brand of nonsense or…. It’s only then that I become angry and vocal and gnu.