That answers your question MG. The reason I am outraged that AA is religious is that courts can order people do undertake it.
Would it interest you to know that not all AA members or AA groups are entirely thrilled about the practice either? A popular cliche is that "AA is not for people that need it; it's for people that want it". So-called "court-carders" are usually at least tolerated, but not all meeting secretaries have an equal capacity for tolerance. I have attended meetings where the announcement was made at the outset: "If you're just here to get a court card signed, bring it on up and I'll sign it right now and then you can get the hell out". (Court-carders usually just sit quietly and scowl, but that secretary may have encountered one with enough resentment and suspicion to be disruptive). Some secretaries will simply state flatly: "I don't sign court cards" and leave it up to the individual to decide for themselves whether it's worth staying.
AA's third tradition states: "we may refuse none who wish to recover". Strictly interpreted, that can be used (and, at "closed" meetings, IS used) to exclude those who have gotten "the nudge from the judge", as well as anyone who does not have "a desire to stop drinking".
The "preamble" recited at the beginning of every meeting states: "AA is not allied with any sect, denomination, politics, organization, or institution". (With respect to the OP, I would argue that the "sect, denomination" part was included specifically to address the question of AA being a "religion", but I guess the definition of that could be almost as subjective -- and, apparently, as difficult to articulate -- as is "spirituality").
"Alcoholics Anonymous is not part of the judicial system. We do not work with the courts or the police department. We do not ask the courts to send people to us. When people do show up with court papers, we are not responsible for making sure the people are sober."
"If a judge, court, school, or employer has sent you to AA meetings, it is because they believe there is evidence that you have a drinking problem. We had nothing to do with their decision -- in fact, AA has no opinion as to whether you have a drinking problem or not."
"While most groups will sign court papers, this is for each individual group to decide. Since AA is not allied with the court system, AA is not required to do the court's work."
"If a chairperson or other group member agrees to sign your papers, they will probably sign with their first name or initials. We are personally anonymous. We are not court employees."
http://www.aasrq.org/courtordered.htm