I kinda agree and appreciate that the article addresses this misunderstanding. But I kinda disagree as well? I, for one, am interested in progressive enhancement to get my product's value proposition implemented as robust as possible. IMHO, this is the business benefit of progressive enhancement and also my advantage over competitors with slow/brittle software.
But again, it's hard to discuss such important architectural questions on the basis of simple examples, so I might be overthinking.