It is relevant, because it's where LastPass' responsibility ends. It's not their job to prevent people from being stupid and choosing a password like `lovelovel0ve` but rather to define a requirement that allows for sufficient complexity.
I think a reasonable feature for a password manager would be to do NIST recommended checks, such as comparing passwords to databases of known compromised passwords and alerting/recommending rotation or rejection of the password if a match is found (depending on password entry UI).
Obviously you're not going to get a complete db of known hacks, but a db of most common X million passwords, updated every 6 months or so, is pretty good, and is what I would expect a good password manager to do.
LastPass is in the bad situation of needing to provide excellent security in a product that people really aren't willing to pay a lot of money for. Some of the websites that ask for passwords are in a better position to do this, but then you don't get the benefits of a password manager.
Same issue for the the other password managers out there.
