If I had lots of unique random passwords then I would have to write them down, which is also on the list of things not to do. I, like many other people, reuse a few which I know and should resist dictionary attacks.
Some things are sufficiently important to merit their own password but most don't. You wont find a list of my passwords and where to apply them outside my head but some of those places are easy to guess.
There is no excuse for using plain text or unsalted password hashes. Just because M$ windows uses unsalted plain text equivalent password hashes does not mean you should too.