Of course it should be taught -- that doesn't mean everyone ought to try ridiculously dangerous feats like Alex did. But the practices that allowed him to do so are worthwhile nonetheless.
Maybe we're operating under two different definitions of "taught" here. You're using "taught", I think, in the sense of giving someone an "impressive feats in the history of climbing" lecture. Which, sure, why not.
The parent seems to be using "taught" in more the sense that a master teaches an apprentice: giving you the skills, yes, but also putting you in that same situation, or encouraging you to participate in such a climb. Like, picture a skydiving instructor, only they're a "free-solo this particular mountain" instructor. They're giving you instruction and practice with the implicit goal of doing this dangerous thing at the end, and with the implicit suggestion that the course will be all you need to be fully prepared to do the thing at the end, with little risk.
Such "teaching" would be very unlikely to succeed; it would more-often-than-not just kill people.
The parent seems to be using "taught" in more the sense that a master teaches an apprentice: giving you the skills, yes, but also putting you in that same situation, or encouraging you to participate in such a climb. Like, picture a skydiving instructor, only they're a "free-solo this particular mountain" instructor. They're giving you instruction and practice with the implicit goal of doing this dangerous thing at the end, and with the implicit suggestion that the course will be all you need to be fully prepared to do the thing at the end, with little risk.
Such "teaching" would be very unlikely to succeed; it would more-often-than-not just kill people.