I reread the original article. The little data they presented made their broad claims seem insignificant. They really seem like they're overreacting to microaggression or something. No one is actually losing their job over this (other than the "Notre Dame vs. The Klan" guy). Professors are just forced to think about what they say a bit more and these two guys had a major forum to whine about it for a couple thousand words.
the coauthor is a lawyer, i think. the article is presented like lawyers argue - a series of anecdotes that they think support their thesis. data would be more convincing regarding the scale of the issue, but anecdotes are not nothing, it's an effective means of communication.
i think your problem with the article is you're looking for evidence that this is a problem of a scale worth worrying about. however, the scale of the problem is not crucial to identifying it as an interesting phenomenon. look no further than your inability to process the mu student v.p.'s words arguing against the media's right to cover their protest. a pure one-off, but fascinating.