I'm sorry but the only good password is one that isn't used on other sites (and only using sites you can trust). The issue, by and large, isn't people guessing passwords, it's websites insufficiently protecting passwords.
Recommending AGAINST a strong password manager is pretty awful. Why wouldn't you want a solution that would let you use unique, strong passwords on each site you use?
The idea that you could do so (unique, strong passwords per site) without a password manager is ludicrous.