To be clear, in many countries with stronger labour laws, "just cause" employment is the national standard -- a requirement. As I understand, the US has many laws that protect again discrimination (hiring and firing), but very few laws that protect all workers from arbitrary layoffs. (Companies can hire and fire as they please with very few severance requirements.) In practice, when you want to layoff low performing workers in places with stronger labour laws, you need to offer large enough severance for them to voluntarily resign. Depending on the country, culture, seniority, and industry, this can be anywhere from 3 to 24 months. Yes, there is a huge variance.

One thing that I don't see being discussed here: If you add "just cause" to your employment contract, you are pretty much trading away future pay raises for security. That is fine, but it needs to be said out loud.

Lastly: I never heard the term "just cause" before this HN discussion. It sounds like a US-specific term. I learned more about it on Wiki here: https://en.wikipedia.org/wiki/Just_cause_(employment_law)