When people talk about "civilization falling apart" or "the death of manners" I can't help but think they are either looking for those things in the wrong place (like, say, a prison or a stockyard), or just sensitizing themselves to those particular offenses against their sensibilities because it gives them something to be good and steamed about.
This isn't me saying that anyone who gets offended is just being touchy. Rather, it's about the way cultivating a sense of offense is insidious.
Self-righteous anger is empowering and addictive. It stokes you up, gets your blood dashing. But it makes it harder to figure out what's actually worth the dander-upping and what's just noise.
If you spend an entire week without someone cutting you off in traffic, and then someone cuts you off in traffic, you tend to remember that affront a good deal more vividly than all the times nothing of the kind happened. That's your brain at work: it's reminding you of things that require a heightened degree of attentiveness, because your brain more or less evolved to make sure your body was not eaten by predators in the Serengeti.
In modern life, where far more often than not you're not in physical danger, such things are counterproductive. They lodge in the craws of our minds, and our higher-order thinking is more often than not hijacked by such effrontery. It's always easy to feel righteous annoyance when you have any number of ways available to you to ignite it. The more you try to artificially induce that state, the harder it is to tell when it's actually warranted.
I've long felt that the people who make loud denounciations about the downfall of manners or what have you are less interested in the preservation of manners per se and far more interested in the preservation of their right to be angry people — how that latter feeling is what they identify as their selves.
I guess the obvious takeaway from that is how it might benefit all of us to learn how to not identify our feelings with being who we are. But because such work runs contrary to the enforcement of power structures, there's a good reason it's not taught in anything like a socially official capacity.