There John Lenton lays out in not so many words that "for the last three years we have worked with the company behind CouchDB to make it scale in the particular ways we need it to scale in ourserver environment. Our situation is rather unique, and we were unable to resolve some of the issues we came across..."
This sounds like a fair assessment to me. No "myths created", no "ignorance perpetuated".
I would also say that for every kind of technology at some point it's fair to say that it does not scale or is not sufficient in other ways.
Or to say it with couchDB: relax!
It's like saying "$hot-software-de-jour doesn't scale" when the article actually said "we couldn't get it to scale in our server environment - which is a cluster of Arduinos powered by solar cells".
There's nothing wrong with having a workload/architecture/environment that doesn't suit a particular piece of software, and if you do it's right to choose something else that does suit your needs. Saying (or implying) that piece of software is bad because it doesn't suit _your_ strange requirements is about as credible as saying "Photoshop sucks 'cause it can't send email!"