I stopped being really active on SO around the end of 2012. I don't think the reason was anything from the article. For me it was 2 fold: the rise of members who criticize everything and the feeling of shouting into a void. I don't have a good name for these users like help vampires. They seem more like Harry Enfield's old "Only Me!" character who show up to say "you don't want to do it like that" without providing a…
Just as you mention, for most questions on StackOverflow, there is at least one "Never Do That!" answer. Nobody seems to be aware that users seldom care enough about the sites the visit to "Read the FAQ" and no matter how many of them you hunt down and guilt, you will never find them all. The site has so much moral righteousness, it's kind of like the "Stanford Prison Experiment" of help sites.
While StackOverflow has many good qualities, it makes the mistake of "blaming the customer." It's an illusion to think you can improve a site by making people feel bad. The energy they spend on hunting witches, would be better spent on ways to fix the quality problem that focus on carrots only.
The problem with addressing question quality by making people feel bad, is that you're setting yourself up to be (ugh) "disrupted." As soon as someone finds a way to get the same quality of results without all the pithiness, and finger pointing, you're at a big disadvantage.