but no one wrote a blog post about how their identity was usurped by the waterfall model

I don’t know about that.

Waterfall mostly died before the rise of blogs, of course, but around the dawn of Agile I remember lots of posts about how nothing was properly designed any more, nothing was ever finished, and you never knew what the specification was.

They used to be real engineers, but now it was just all chaos! They couldn’t design anything any more!