Well, I cannot say for other people, but if other people are anything like me, then it is natural not many join the modding community or online games. The thing is, most people interested in this stuff have joined the game long ago, and many of them have quit after playing for many years. And new players have difficulty getting used to such old games. Personally, I bought NWN1+NWN2 collection from GoG as late as in fall 2013, and I did it mostly because I wanted to fill the gaps in my "gaming culture", to play through a few classic old games I missed in my gaming "career". I only intended to play through the 3 official campaigns, and after that I quit, as I thought, for good. I only came back a couple of months ago, after I saw a video on Youtube of someone playing Blackguard module, and I decided to check out custom content "just to see what it was". Ended up totally hooked to the game and the toolset. But most other people don't get to this second phase of playing custom content: they've played through the official games, decided that their "gaming library" had some gaps filled, and moved on to newer AAA games, of which there are dozens each month.
I believe Sword Coast Legends may reignite the interest towards D&D games, and maybe someone will want a bit of a more "true" D&D experience and turns to Neverwinter Nights as well. But, given how powerful the campaign editor they are building, I am afraid there is a possibility that that game will become the main game for RPG content creation, and even fewer people will be left here.
I don't think it matters though. In my old school opinion, 100 people devoted to the game is better than 1,000,000 people not taking the game as something more than a momentary distraction from the real life. There is a Doom community with, at best, 1,000 active map makers and maybe as many gamers - and you should see what these guys make and how they play...
