Thats a fair question Andrew and easily answered. Its a self imposed limit. As I think I remember mentioning to you before, a forum is no longer our main focus, more of an add on (and now called a Club)..so that we can do other things with the website, not just spend the entire time moderating large numbers of people as was done in the past. We've done that bit now. Large numbers almost inevitably results in massive amounts of difficulty and consumes massive amounts of time.
With 60 people, if everyone plays their part, we can have effective discussion. Even if there are large amounts of people on a forum its almost always a centre core that run it forward.
Am enjoying your postings Andrew so keep going.