Bitter vituperation towards the failed beta, even after it's gone, may do as much to drive away readership as the beta
A First, on the bitter vituperation, as one who quite unabashedly shared my thoughts about how and why the new design was/is bad: much of the speech was strongly voiced, but it was simply the truth. If Dice kills the site layout and function, I will stop coming here. That's not a threat so much as a fact that I feel dice should be privy to. I don't want them to kill the site, and I'm sure they don't want me to leave. Bluntly pointing out the lose-lose seemed to me the most direct way to communicate my feelings and affect change.
As an addendum to the above point, there is something in the culture here (and not just here) where humor and bravado is acceptable and even expected. Perhaps you have not been properly acculturated to Slashdot geek, subspecies of Internet geek. By your very presence here you should know what to expect in this regard.
B Second, Dice failed hard on this gambit. They didn't even bother to try at "reading the wind" so to speak. Hopefully they have learned from this and will at least make an attempt to understand the community before making fools of themselves in the future.
You can say that the community reaction harms the site's image, and that might even be true. On the whole though, the community doesn't care about Slashdot's image. We have this space, and it is ours, and it is good. Only Dice is concerned with image because they are trying to figure out how to grow us and monetize us. This is the ugly truth behind the whole situation, and I posit this is where where much of the "bitter" response really came from. It's creepy and sad to see a culture that you love slowly destroyed by a soulless entity that doesn't care about you or your community so much as it cares about using you and shaping you into something profitable.
In this instance, by failing to read the wind, Dice bared this truth to all of us; reminded us that this community isn't really ours so much as it is theirs. Absolutely that was a hurt to the community.