1) you won't change passwords and won't make them unique for each site
Why not? Doesn't take long to write them down

2) You won't make them complex and long
I recently read an article that said complex and long isn't necessarily best . . . but password rules don't let you make the safest passwords

3) It won't be with you when you need it. (You can carry an app in your smart phone, but that metal box is a PITA)
I don't have a smart phone. My sole access to the web is in front of me on my desk.

4) You'll leave it unlocked and that piece of paper will sit around unsecured on your desk, table, counter etc.
And just who's going to be rummaging around on my desk out here in the boonies? And good luck to anyone who does . . . it's not the most organized desk in the world.

As I understand it, the biggest risk is from hacking robots in Russia, etc., not a local druggie looking for cash. Anyone casing the area would see the '94 Saturn in the driveway and keep driving past.