Well presumably because it doesn't really matter. The type of org that will do that is the type of org where employees are a widget, to be added, replaced or removed as required for the machine to operate. Anyone comfortable with working in such a situation must acknowledge that the org does not care about their feelings, why would that suddenly change during the termination process?

This is recent knowledge though which only became commonplace after Millenials entered the workforce. There is still an army of people out there who are teaching their kids completely antiquated labor relations knowledge under the delusion that a job can be "for life" these days.

There are people in their 50s and 60s who are learning the hard way (particularly in 2020-2021) how much their company doesn't actually care about them.