This is not a (political) troll..."why teach algebra?"
I know you sincerely do not intend it as a troll, but since "why teach X?" is ultimately a social question, it would seem impossible for this to remain a technical or even philosophical discussion. (Personally, I believe the whole issue is moot (ie arguable but of no significance). As, inevitably, the effectiveness of automation improves and the wealth of the world grows, the fraction of humanity for which it is of value to know anything about anything whatsoever is rapidly becoming asymptotically zero...it's all ultimately "enrichment exercises" for which there will uniformly be decreasingly compelling pragmatic (versus esthetic or moral) justification (which was the sort you were soliciting). I view this evolution as a good thing, but recognize others may not, and agree math-fun is not the best venue to contest such positions, so I'll leave it at that). --Marc "Restore the Trivium!" LeBrun