I've been through reddit, usenet, and the chans, and I'm part of the programming culture (one perhaps more acidic than most), so I do detest censorship. (ie, you can't say that sort of thing/express that sort of opinion here). But that doesn't seem to be where Imzy is coming from. The use of a chan/usenet style most recent system as opposed to reddit-style voting also shows that Imzy seems to have a good understanding of how corrosive "internet points" can be.
Community moderation can be a good thing. HN and 4chan are living proof. And if your criticism is "but my freedom of speech," xkcd.com/1357/ gives the explanation for why that's wrong.
Basically, I think that if Imzy is well-run, it could be a very good site (just like the good parts of reddit). However, if it's poorly run, it will end up as an endless cycle of agreement, with any dissent leading to an immidiate ban. Time will tell.
There are plenty of sites out there for those who wish to express themselves freely. Well-moderated sites are considerably rarer, and we could use another one.
But hey, maybe I'm crazy.