Because that one password is pretty long and secure, and you enter it only on your own machine, into one known binary, no-where else. It strikes me as sensible

Because that one password is pretty long and secure, and you enter it only on your own machine, into one known binary, no-where else. It strikes me as sensible advice. Connecting your password manager to the browser for auto-fill already compromises the security, granted, but what other flaws have there been otherwise?