I agree with the idea of not maintaining an intermediate representations of things that serve no useful purpose. But the pattern the author argues against isn'

I agree with the idea of not maintaining an intermediate representations of things that serve no useful purpose. But the pattern the author argues against isn't necessarily bad. Certainly not an "anti pattern" or against "the spirit of the law". Take their own example. An app may very well render a certain set of "nav items" to JSX in multiple ways. In that case it probably makes sense to define the common parts separate from the JSX -- otherwise you'd have to maintain each list of nav items in JSX separately.