Well, having been through several waves of reddit influxes all I can say is that like in real life, people try things out before finding out what the deal is with this place and that is probably why a lot of people don't stay from said influxes.

From my view, this site is all about engaging with our interests and with each other through conversation. Sounds simple, but it does require more effort than it might seem at first glance. I've noticed that a lot of comments from influxes respond to the article or video, but not to the rest of the community or at least don't really invite conversation, merely "I think this." I'm not pointing any fingers at any users, it's just an observation.

So just because someone is posting content doesn't mean that they are inviting conversation. There are users who do nothing but post links to their own websites and unsurprisingly, are not much paid attention to. Then again, there are users who do that, but their posts do gain traction because they're posts worth talking about in the minds of the user base.