My concern with password managers is that if the password database is stolen with my master password, I lose everything. If this script is stolen off my laptop, what do I lose? Attacker would have to guess so much. Even if they did guess all 3 'passwords', they would still have to guess the site, username, etc. Plus, my master password isn't stored anywhere on my machine.
I don't care about forgetting a master password. I can recreate everything.
The flip side is my master password IS distributed across multiple third party datasources that I have no control over....