Earlier quoted context omitted.
In addition to that, I know that, at least in the Bay Area, there has been a consolidation among smaller recruiting firms. That may contribute to the decrease in job postings.
Also, big companies like Google have offed their recruiting arms, or at least large portions of them. This is a red herring metric, at best.
Recruiters are often the first victims in a downturn. So I would say the effect would be even more pronounced. Besides consolidation among smaller firms and layoffs of in-house recruiters, many independent recruiters have moved away from recruiting temporarily and may or may not return when the climate changes. This happened in the early 2000s also. The net effect is a dramatic drop in duplicated job postings on the major job boards which, to an outsider or a Techcrunch writer, is interpreted as a dramatic slump in tech hiring. As usual, statistics are easy to misinterpret depending on how willing you are to look beneath the surface.