It comes off as overly cynical, but this seems to me to merely be the removal of a veil of ignorance about what people actually think and how they actually want to behave when they are either anonymous or not present physically (with the possibility of having their mirror neurons engaged, physical assault, in person shaming, etc).
If it wasn't obvious beforehand, then it must be obvious in retrospect that a culture war was the inevitable result right?
While I agree that the responsibility falls on the individuals taking part ... pragmatically isn't the outrage economy going to work for a long time? And the physiological tools for encouraging uncivil behaviour just going to keep getting better for a long time? I have my doubts that any significant percentage of people will be able to follow that path of individual responsibility when so many smart people are constantly trying to nudge them off of it using subtle methods the targets don't even understand.
Calls of "can't we all just get along", whether directed against physical violence or uncivil discourse, however correct, never seem to do much when the problem is occurring in a system that benefits from the opposite.
What seems to have happened is a mentality change. Rather than seeing ads as a funding source for journalism, journalism (or a watered down variant) has become the means of pushing ads in peoples faces.
I would argue that this impression comes from the fact that media options were much more limited in the recent past, and therefore had to appeal to and not offend a wider range of audiences than current sources. Watching TV programs from the 50s/60s, for example, they do seem quite polite and civil. Now though, options abound. Why should I watch a whitewashed and generic news program when I can listen to vitriolic talk radio or scroll through my website of choice and see exactly what I want to see? Not to mention that every "jerk/bozo/asshole" can pour his heart out online.
The downfall of the previously-more-mainstream Mainstream Media has simply enabled more impolite and "uncivil" voices to stand out from the crowd (for better or worse).
As far as personal and professional interaction, the responsibility for maintaining civility in such environments falls on the individuals taking part. Don't tolerate bullshit from employees. Be respectful to your friends/family, and expect the same in return.