A finger can easily be forcefully used or even removed for use later. A password however is still harder to get out of a brain and can be just as strong if it is long/complex enogh.
I don't think getting a password out of a living brain is harder than removing a finger. Most brains would give you their password if you threaten to remove a finger, even more if you give a demo first and threaten to remove a second one.
In the case where the brain is dead, removing the finger is way easier.
I am not sure how that balances out, but I am sure two-factor authentication (fingerprint plus password) beats either.
