You have to create an account for some random forum to read a comment? You'll never probably log in again? Even if you go there once in a while, do I really care if someone discovers what my password is?
Do I have a secure and unique password for my bank account? Sure.
My Facebook account? Yes.
My Slashdot account? Maybe.
My somerandomforumthatmademeregistertoseeapic.com? "password". Or "Password", "password1", "Password1!", if the admin is paranoid.
Is it secure? No.