AJR examines the quality question. In one section of the story, author Carl Sessions Stepp notes that one paper reports a decline in errors after instituting a checklist of sorts. That could be a factor. But I wonder, too, if it's really about readers simply not caring anymore. If we don't, why should they?
When I first went to work at one paper, I was shocked at how readers who called to complain about something seemed to act as if they owned the paper. It was their paper; they were mad at some error or perceived bias. By the time I left, the clerks were noting fewer, less passionate calls. They seemed to have given up.