I don't think its all that odd. A lot of folks join but don't post. They follow along with discussions as well as research topics they are interested in. At any given time we have 30-40 members logged on. But not many are posting.
While its possible a few new members were bots (I look at all the new registrations emails, ips, etc.), we have implemented the latest in spammer/bot prevention here on CR. Typically spammer/bots are going to sign up for the purpose of making posts and we haven't seen much of that either.
Members like you and Larry for example are one in a 1000. At the end of the day, its a numbers game. But my forum observations over the years indicates that we are at a point where growth and activity increases.
When members post, it encourages others to post as well...draws them out of there shells a if you will. If nothing else, it provides the lurkers more material to read while they are visiting CR.