It's dehumanizing to have thousands of people passing through our computer screens, so we do things we'd never do if those people were sitting next to us.
It's too overwhelming to remember that at the end of every computer is a real person, a lot like you, whose birthday was last week, who has three best friends but nobody to spoon at night, and who is personally affected by what you say.
Even if you remember it right now, will you remember it next time you're overwhelmed, or perhaps never forget it again?