So I am the first to be to blame for this. I didn't realize that for the past two months I had accidental not allowed new sign ups.
I also have gone ahead and changed the forum a bit, going to maybe try and put the sign up bar above the fold for none signed in users.
I will also start a write up on what I have done to make a site of mine go from a launch on ProductHunt on Dec 5th, to now over 3 million unique visitors, in less than three months.