The uni I am going to right now, focused on technology, decided to use birth numbers (similar to SSN I guess) as a password for housing accounts of new students.

Birth number isn't even treated like something that should be super private. I think it still is considered private information like phone number and email address, but its only purpose is supposed to be identification. Some 4 digits that are chosen somehow + date of birth.

I was also surprised to just get sent the password for another system by email in plaintext.

Better than McDonald's security I guess: https://bobdahacker.com/blog/mcdonalds-security-vulnerabilities