Although I have have met and currently work with many people who struggle with direct interactions to an extent where one could consider it a personal problem,

Although I have have met and currently work with many people who struggle with direct interactions to an extent where one could consider it a personal problem, I have also found that people who are direct or don't "beat around the bush" also often get VERY upset when treated similarly. I'm not saying that there's no space for direct communication and that everyone needs to be formal and socially polite during every interaction. But I've met many people who act like you describe John does who very much do not appreciate getting it back, implying some level of awareness that their directness is hurtful on occasion. I've only met a few direct people who can take it as well.