If a burglar steals it, you can run at the bank to take your 'backup list of passwords' and start changing your passwords.
If you lose it, same thing.
Then you re-create another book so that there's always one in a safe at the bank ; )
I've got a list of all my passwords, without any encryption, in a safe at the bank. They serve two purposes: in case I forget my passwords (I do write them down at home in some 'encrypted' form that is not meant to resist the NSA but that would stop 99.99999% of all the burglars on earth) or in case I die (my family would then be able to access my various online accounts).
This is not inspiring in me further confidence in the methodology...
The probability of your home or work place getting burgled is probably lower than the chance of the N random websites you have passwords for getting hacked or burgled.
I adapted it to carry my passwords in my wallet: http://blog.jgc.org/2010/12/write-your-passwords-down.html
a) keep it physically safe
b) use a relatively simple, memorable cipher (e.g substitution)
c) use a different password for each site
... rather than trying to get them to use LastPass or Password Safe or the like.
A kindle version of this would probably qualify for 'most ill conceived' however ;)
It's more portable that software password managers, though the passwords are likely to be less secure. Then again, I keep ending up having to narrow down what characters I can and cannot use in a password after generating them, so you can't make as much use of that as you'd want. A lot of user will still just use '1234' everywhere, but for most users it might actually be pretty good.
On top of that, having a list of accounts makes it easier to cross reference them when you see a news report about a site's password database being leaked.
Chance of burglary: ???% Chance that one of the 1000 sites you signed up for gets hacked because they're bad at security: ???% + 1
I'd much rather buy this for my grandparents and have them use 1000 complex passwords than have them use one password for everything and have them be screwed when X Service gets hacked.
But let's be serious, this isn't going to get stolen.