A gaming sub free from the hype and oversaturation of current releases, catering to gamers who wait at least 12 months after release to play a game. Whether it's price, waiting for bugs/issues to be patched, DLC to be released, don't meet the system requirements, or just haven't had the time to keep up with the latest releases.
I've never played any of the Diablos, or met anyone who has. But they are obviously popular for a reason. Are they worth going back to the first one?
Edit: Thanks for the answers, the community is alive! Based on you recommendations it looks like I'm going to give 2 resurrected a try.
Appeal of Diablo in general, or 2 specifically? For 2 specifically, it's a lot of nostalgia. It was one of the most popular games when it came out and for years afterwards. A lot of the aspects of the game design still hold up really well even today, and still draw you in with trying to get more loot, trying a different build, etc.