“the vast majority of author-pay open access journals don’t give a flying futz about their reputation” – This is something hard to explain to people who don’t actually write papers and apply for positions. Yes, the *majority* of journals are crap, but that doesn’t mean this is relevant to us, because no one is reading these journals. Heck, they are not even in Pubmed, so impossible to find or see. If you work in science, you cite or read at most a dozen or so journals, maybe three dozens, and these are always the same. A crap journal is pretty obvious (and even easier with this website). Articles in crap journals won’t be useful in a CV, unless the jury is in a totally different field, which they shouldn’t be and even then a crap article in a CV is a big risk.
So yes, there are many crap open-access journals, but in practice that’s not a problem. To the public, we only have to communicate that in the age of the internet “being published in a journal” doesn’t mean anything anymore and is not by itself an indicator of quality, just like “being published on the internet” doesn’t mean anything. I imagine that many readers of the blog here are looking back to the age of printed information and would love the internet and open-access to disappear, but there are so many advantages of open-access that the small inconvenience, crap journals, are not a problem in practice. Only strange people or scientists from weird places will ever submit something there.