I say give em a break. Some will eventually post. If not, no harm no foul. To the lurkers. Introduce yourselves. We don't bite!
You know something, you are correct. A previous slotting forum I was on, I joined and lurked for 3 or 4 months before I ever posted. I was hesitant to make that first post. But once I did I felt very accepted and never hesitated again about posting. I am sure that is the case with a lot of the folks.