Someone who posts a lot will be more familiar. That certainly counts for something. There are long-time posters who I ignore, and ones who I pay more attention to. You build a rapport.
New posters are just generally less familiar with the spirit, the trends (how many of those Mass Effect 3 threads were from relatively new members who thought they were saying something new?), and the standards. Whether it is a good thing to admit or not, I do expect less from new people. But on those occasions where a new poster does say something truly interesting, I take special note. I make sure to say, "Welcome to the Escapist" in those cases.
But it is mostly the rapport. I wouldn't say I'm friends with people here. But there are those individuals who I would miss if they left or were banned. And it's hard to build a rapport with someone with very few posts.