One thing I've noticed is it looks like the site, at least the OT where I stay most of the time, has stopped growing. Look at the majority of the threads and you will see mostly people who have been here 2+ years with rather high post counts. Very little, if any, new blood coming in.
I think you are wrong here. The subset of this site that is the OT gets its posters mainly as people that wonder over from the SEC and Tiger Rants or when new, high profile news stories break.
I looked on the first page and it seemed that at least 5 or 6 of the 20 threads were started by posters who had been here 2 years or less.