Dan points out that there's nothing about Algebra II in the Andrew Hacker piece that started this discussion, while my post was only about Algebra II. This was not a clever gambit on my part, in my mind the piece was about Algebra II. Doing a little mental and RSS forensics, I think it is because Dana Goldstein used this quote from Anthony Carnevale in introducing her long quote from the piece:
Education reform has stalled on Algebra 2. The more you demand it, the more drop-outs you have.
That bled through into my reading of Hacker. I do agree with Dan that:
The argument that we ought to limit second-year Algebra (with its strict rites and rituals of symbolic manipulation) to people who volunteer for it is a much easier argument than saying "all Algebra oughtta be elective." Given how much of the automated and programmed world relies on an understanding of variable representation, I don't really see that argument.
On the other hand, it is even weirder that most of the defenders of algebra are making rather indirect arguments. You do need to understand variables.