It's news to me that not responding to a post implies approval.

Sometimes it means that potential responders never read the post, either because of time, becaused the post was missed as it went by (easy to do if you drop in intermittently), or maybe just because the poster is an asshat who rarely has something useful to say.

Sometimes it implies that the poster is such a supreme blockhead that attempting basic reason in response is like trying to hammer cooked spaghetti through a brick, so nobody interested in reasonable arguments responds.

But it sure doesn't automatically imply approval.