>inb4 you are a loser for using that board
It doesn't have to do with the seconds. When I first try to post the thread, it says "4 seconds". When I try it again, "it says 8 seconds". The pattern continues.
This isn't the first time this happened to me on /r9k/. It's like I can't post on the board at all.
The rule is not new by any stretch of the imagination. /r9k/ was created as an homage to an xkcd comic where the author speculated that a filter of this sort could drastically improve the Internet. Testing thishypithesis by implementing that filter is literally the reason /r9k/ exists.
The rule DID get suspended for a while: about a year ago, I think it was. They put it back in place a couple of months ago.
And yes, only losers use that board nowadays. It wasn't always that way, and I'm not sure how or why it was taken over (the takeover happened before I started coming to this site). But at this point it's nothing but a containment board, much like /pol/: kept around only so that its users don't start shitting all over the rest of the site.