As I got it, parent comment wasn't about having stable (tested) packages, but automated measures to recover one's ass when a bug slips through (or when you just

As I got it, parent comment wasn't about having stable (tested) packages, but automated measures to recover one's ass when a bug slips through (or when you just want to risk or whatever) and update leaves you with unuseably broken system. This sort of situation has happened to me on various distros, and Ubuntu wasn't an exception.