Almost every Nas fan I know is in their mid to late 20s (myself included) or beyond and doesn't really post on forums anymore. I doubt he's really picked up a wave of new fans since the early 2000s. SD was meh to many and he definitely didn't endear everybody with HHID or Untitled. A lot of people couldn't get into DR and saw it as a niche album. Commercially he hasn't really had much notoriety since God's Son with Made You Look and I Can. Then of course there are the legions of people who just never cared for Nas to begin with. With LIG he got back on track, but the verdict is already out on Nas for most people, either they like him or they don't. Even a lot of his fans have been wavering over the years but it seems like he got some of them back on board with this one.
That's just how I see it anyway. I can understand the lack of forum appreciation for Nas these days.
As a Nas fan.. I wont go against this. I do think he's maintained a fan base more than gained..but that's cool for a 40 year old rapper..