I don't understand your response. Whom or what was he unfair to? What technology was he 'lambasting'?
But don't criticize them for being slow, and then in a
postscript say "and I don't need the actual results of
this algorithm, anyway."
I don't see him criticising any solution for 'being slow' in general. Only for 'being too slow for this specific problem'.
It's very common to use a (already available) algorithm to calculate a result related to what you actually want and then infer the answer from that result. E.g. calculate the intersection of two sets and then count the members, instead of intersecting and counting simultaneously and never having the intersection available. It's usually a wise decision to use such the first approach: the performance penalty is acceptable and the advantage of code reuse (and not having to write and test a new algorithm) is larger. His point was that in this case, it wasn't.
It's very common to use a (already available) algorithm to calculate a result related to what you actually want and then infer the answer from that result. E.g. calculate the intersection of two sets and then count the members, instead of intersecting and counting simultaneously and never having the intersection available. It's usually a wise decision to use such the first approach: the performance penalty is acceptable and the advantage of code reuse (and not having to write and test a new algorithm) is larger. His point was that in this case, it wasn't.