Just about every Lifering meeting I've gone to has turned at least periodically into an AA bash-fest, so certainly some secular support group meetings do attract people who are angry about their experiences with AA and want to share them. I think at some level that's helpful, for them, which is what matters. People who don't like religion tend not to stick around AA, people who can't stand AA tend to collect in the non-AA secular meetings, which is all fine. Whatever helps, helps, and there are plenty of different support options, especially online.