This merely gives the user a false sense of security. What if a hacker get hold of your master password? I rather advocate the use of different high-entropy passwords divided in security tiers. A junk password for places you don't care about or fully trust, a generic password to use on trusted services and secure passwords for crucial services.
People would have to gain access to my machine, plus figure out my master password to compromise me. But I gain unique, random, 24-32 character long passwords for all my log ins. I think the benefit greatly outweighs the risk.
