Andrew Hacker and nearly everyone else is missing the point.
Taking an algebra class for many students is not about the algebra, it's about learning to think. Even if you never use algebra again, the process of learning algebra is mental exercise that improves the mind. Taking a foreign language, studying biology, learning economics, studying history - it doesn't matter what the subject is, merely the more you learn the better a learner you are, and the better thinker you are.
In sports we see athletes perform all kinds of exercises that help develop skills used in their sport, but are never used directly. Ever see footage of a football player stepping through tires? Ever see one do that during the game? Ever see footage of a quarterback or pitcher throwing the ball through a hanging tire? Ever see them do that in a game? Athletics is filled with examples of training exercises done to hone one's skills for a game, yet we have difficulty accepting that mental exercises hone skills we need for life.
Last night I was a volunteer at a 3 hour long dance recital held at a theater (you know, a building with a stage down front, seats, and darkness...) Parents were told in writing, at rehearsals, and at the beginning of the performance - no electronics. No phones, iPads, Nooks, Nintendo, MP3 players, DVD players, etc, etc, etc. In fact, they were told that if a small child needed electronics to be entertained, they child should be left at home with, gasp, a baby sitter. And, of course, there were countless people who ignored the rules, including parents trying to keep small children quiet by using small DVD players. And, when I politely asked them to turn off their devices, they gave me crap.
The problem more universally is that people no longer know how to behave, and no matter how well the rules are promulgated, they believe the rules surely apply to everyone else, but not to them.
Truth is free, but information costs.