[j2kun]

Yes, and in the hands of a brilliant artist, mud and coffee stains can make a lovely painting. That does not mean art teachers should use mud and coffee as the only tool for teaching one how to paint.

Unfortunately, most high school math teachers are undertrained, underpaid, overworked, and pressured to focus on exams. The two-column proof is a crutch. It's not the only awful part of high school math education, nor is it the sole bane of a student's math education (I never said it was). But it is the most egregious example of bad math education.