No offense, but it's essentially a dead-forum and to make it invite-only shows the bigger picture is out of their grasp. I hope they open registrations and shape itself to be something...anything.
While it's still in its early stages, we want to future proof things quite a bit. Currently, we can map our users onto a directed graph which will help immensely with spam, dead accounts and so forth. (If you're a spammer, everyone you've invited gets their account nuked along with the person that invited you.)
Also, one of our users put together a sweet visualization of this in action, which you can see here:
As an aside, I just tried to register without a referral code and simply got a 404 error.
I believe in a meritocratic system. If you contribute with good information, insight or whatever resource you want to call it, you will be rewarded well so the community will be.
Just think than one asshole with invite can invite another 23 assholes. Then you're beloved community will be ruined and "invite only".
My point was, yes, the site needs polishing, but save the judgement of the community and its curated content until after it has had the chance to gestate a bit.