I was raised in the Friends culture, and find this characterization skewed. "Honesty", yes. "Even if uncomfortable", sure, often, but only literally speaking. But I've never heard a Quaker in my life extol "uncomfortable truth" in those words. Because, realistically speaking, "telling the uncomfortable truth" when declared as a principle is 99% of the time just a wordplay excuse to be an asshole or to be petty (which I assume is why I never heard the Quakers in my life use that phrase, since they tend to be not only honest, but also kind and pragmatic).