It definitely gives me pause. ESR clearly doesn't know when he's out of his depth (classic Dunning-Krueger).

I'm not enough of a programmer to judge his programming texts, though I am enough of a sysamdin to find his Unixy sysadminish stuff generally valid.

I've found CatB itself aging poorly and question a number of the assumptions behind it, particularly as concerns anthropology. It seems shaky. Though I think the general principles behind Free Software and the open source model have their merits. Just, possibly, not quite those ESR describes.