I also tried to start a discussion about this in the thread, but all I got was "shut up troll" / "you just want to buy them cheap" and more comments like that.
Even if Dreamcoin is not a scam, I don't have the faith the Dev can really implement Zerocoin. I asked him some questions about that through PM, but it looks like he doesn't like to answer complicated questions.
I generally dislike using the term scam unless it's completely obvious. It is possible that both coins had plans to implement zerocoin and didn't realize that it wouldn't so easy. And since zerocoin has been discontinued by the original devs, I really wonder how dreamcoin could possibly even say they can pull it off.
At least liberty coin has backtracked and is removing the zerocoin references.
But as I mentioned before, it probably doesn't matter. Trolls and fud is so rampant here, that any negative comments or critical thinking sometimes gets misconstrued as trolling. It's assumed everyone has an ulterior motive, so if you are saying something negative, you must want the coin cheap for yourself.
It'll happen in a forum like this with little to no moderation. That's what occurs when trolls run rampant in the streets... everyone begins to look like a troll to you. And there is the simple fact that coinholders don't want you to lower the value of their coin, so they'll overlook neg comments/try to dismiss them -- human nature.