Yup, the examples were where the thesis was politically incorrect. For instance, there were a number of graduate students in Soviet history who made careers claiming that the Soviet Union was more violent than the politically correct, leftist historical mainstream narrative depicted. Similarly, I know a graduate student who made a career out of showing that the Amish were actually much more tolerant and respectful toward women than the historical mainstream narrative depicted.
There's a large gap between saying that the hounding of Summers was a witch-hunting campaign, and that one can't trust many academics on issues relating to race and gender. The latter is a categorical and absolutist statement, one that does not nuance then situation in any significant way. It doesn't acknowledge that weak evidence is still evidence, or that plenty of academics - such as myself and apparently you - have more complex and nuanced takes on women and gender and race.
That is evidence that historians can be trusted, although the Amish are clearly "others" and so defending them isn't really that politically incorrect.
"There's a large gap between saying that the hounding of Summers was a witch-hunting campaign, and that one can't trust many academics on issues relating to race and gender." I don't agree. The hounding was widespread and sent a clear message that you risk a lot if you take a politically incorrect position on issues of race or gender. If there is a group of 1,000 scholars and I believe...
Here's my op-ed that uses long-term orientation, probabilistic thinking, numeracy, consider the alternative, reaching our actual goals, avoiding intuitive emotional reactions and attention bias, and other rationality techniques to suggest more rational responses to the Paris attacks and the ISIS threat. It's published in the Sunday edition of The Plain Dealer, a major newspaper (16th in the US). This is part of my broader project, Intentional Insights, of conveying rational thinking, including about politics, to a broad audience to raise the sanity waterline.