And I am left thinking, if in the future I see a coworker leave on the day by his own choice. I wouldn’t hold it against him. The company has shown how easily they are willing to let go of a huge number of people. Why should I be mad at any of my coworkers if they decide to leave on the day? The company already set the bar for how this works.
I've quit without notice once in my career. I already had the next job line up though.
Leaving without notice is a good way to alienate a lot of contacts that most people will really want to maintain. But even beyond that from what I understand most places have policies in place to prevent employees coming back if they've left without notice.
Meanwhile, if my employer fires me without notice and I've got a mortgage, mouths to feed, and/or medical bills, then I don't really have the leverage to say "I'm sorry, by firing me without notice, you are ineligible from asking to rehire me."
There are A TON of people people who would probably love to walk in and quit tomorrow if they had another job lined up or the means to go without one for a short while.
Except in reality, almost nobody can do that, because they need to eat and pay rent. And if you did, you'd burn a lot of bridges.