Because from the sound of that, it feels that it would patch the `123456` problem, but opens up a new vulnerability - the password is known / being sent through / printed, so it can be leaked from that source.
On the other hand, how would we make "lazy" people use those? And ensure that won't reuse the same password on some vibe coded forum that will store them in the plain text and get hacked in a few weeks =)
That's why I mentioned that mindset shift as the prerequisite.