Well people arent going to stick around if they got nothing to say so or not feel welcome or any other reason so, thats just normal everywhere. Nobody is expected to spend their entire time on just one site and post every single day, unless they really have absolutely nothing else to do.
Some people LOVE meetings but others HATE them and avoid them like the plague. Why because they take up so much of your time. So its the same kinda deal with forums. But benefit of forums its written down so you dont have to sit there and get earbashed then if you were if you were speaking out loud.