The decline in number of editors seems to have started at 2007 given figure 1. I wouldn't tie the amount of negative press to the decline in editors.

The point about there being less new stuff to write about seems apt, what do you think about the counter points that the article had?

"First, as noted above, the vast majority of articles in Wikipedia are still below community standards for “good” articles. Second, underrepresented groups still find it challenging to join. For instance, one study found that only 9% of edits are made by female editors, and that articles of particular interest to women are shorter than articles of interest to men (Lam, 2011). Until editors are representative of the population of potential contributors, it is difficult to argue that the socialization practices are sufficiently effective."