The relationship between librarianship and citizenship is a shifting one, and it's not always clear how they're related. The SRRT types want the distinction erased entirely, since the only thing that matters for them is politics. There's no such thing as professional autonomy for people who collapse the personal and the political.
The AL moves back and forth from one to the other, I think. I've been considering which domain the AL belongs in because of one of the commenters to the Porn Challenge post who said that academic librarians, including me, just don't "get" public libraries. To a certain extent, that's probably true.
While I have in the past from childhood on been a regular user of public libraries, I've hardly set foot in one in years. As my reading tastes broadened beyond the popular taste that drives so much public library collection development, I found that usually only academic libraries, and even then only larger ones, could possibly satisfy many of my tastes. If your library has fewer than a million books in it, I probably wouldn't want to use it. This story about the Kansas City library struck home with me. Public libraries, at least smaller ones, are next to useless for people who read scholarly or esoteric or just non-popular books for enjoyment. Part of the reason I became a librarian was to keep access to good libraries and not have to depend upon public libraries with their implicit assumption that unless everybody wants it, nobody gets it.
And before you protest that I could just interlibrary loan everything I wanted, let's just say I don't want to do that all the time. I like browsing the stacks and the serendipity of discovering a book I don't know in a subject I like. In public libraries outside of large cities, the chances of doing that are a lot slimmer unless you like 3-year-old bestsellers.
So I'll accept the charge that I don't "get" public libraries. I don't think it's completely true, but for the sake of argument I'll agree. I think it's more likely that I don't "get" many public librarians, but that's neither here nor there. Thus, when I comment about public libraries, which I sometimes do, I'm not necessarily speaking as a librarian. Just as I'm sure there are plenty of public librarians who don't know much about building a research collection or working with graduate students or the joys of dealing with Elsevier, I don't know much about buying multiple copies of the latest bestseller or working with children or the joys of dealing with rowdy teenagers.
When I speak about public libraries, I speak as a citizen. All libraries serve a public, but the public of academic libraries is scholars and students (with some exceptions). If you're not a scholar or student, then you're not part of my public and I'm not in the least accountable to you. But the public of public libraries is the general public, and it turns out that, in my capacity of concerned citizen, I am in fact a member of the general public. So regardless of whether I "get" public libraries as an academic librarian, I have an interest in public libraries as a concerned taxpaying citizen who is capable of political and moral reasoning and has an interest in the public sphere and the educational opportunities of my fellow citizens in a liberal democracy.
Therefore, I don't have to share the ideology of the ALA and many public librarians to make valid comments about public libraries. I am a citizen, and my taxes help support public libraries. As public institutions supported in part by my tax dollars, public libraries are accountable to me as much as to any other public institution. My library porn challenge is the challenge of a concerned citizen who thinks the ALA position on public pornography is both intellectually confused and morally harmful. To imply that someone who doesn't "get" public libraries has nothing valid to say about them, as my critic implied, is to say that only people who already completely agree with the ALA's ideological positions can have anything valid to say about them. But there's a name for that sort of fallacious argument. It's called Begging the Question.