Why is the dialouge between humans always besmirch others whom we know and perhaps love?
Very simply because humans have several misguided quests to be competitive, socially accepted, and interesting. Since we know the strengths and weaknesses of those we know and love more than anything else, and such social norms are what everyone has in common (you may think paint drying is interesting, and it may be, but very few people will care or relate) , these are the things we share with each other. Also, many of the things we complain and criticize each other for are the things that annoy us the most, so expressing this form of anger helps many deal with these imperfections. Very few people are separated from these tendencies, and admittedly I am not (though I try my best), and it is just how people are. Don’t know what you wanted from your question, but the true answer is pretty depressing. You can email me if you have any philosophical questions at all. Good luck.