Yes, that's because if you think posting blog comments is a way to "build links" you're doing it wrong.
I cannot think of any way to put this any more plainly: DO NOT post blog comments if you're just there for the "link."
Post if you have something useful/interesting/entertaining to add to the conversation. Period.
If you happen to get a link from it, that's cool -- but "getting links" should never, never
, never ever ever
be the reason
you post blog comments.
Blog comments that are only there in an attempt to get links are SPAM, pure and simple. SPAM.
And blog owners who care about the integrity of their blogs will
delete them, as they should.
Blog commenting is NOT EVER a valid "link building" activity.