Cars are different. When people lose their cool in their cars it’s often due to other semi immediate pressures such as getting to work on time, picking someone up on time, etc. Mostly a time pressure. Other times it’s because of perceived slights to driving etiquette, or to their person. Why is someone weaving in and out of traffic and violating etiquette and causing potential dangerous situations? Are they just speed demons, or are they trying to “get somewhere in a shorter time”?

Online discourse is not subject to the same pressures. Yes, people get offended and some people like taking offense, and that triggers some similar reactions, but I think the dynamic is different. I could be wrong.