I still think a lot of it is because social media wasn't really a thing back in those days. I mean yeah, Myspace existed, but that's about it. There was no Facebook, no Twitter, no tumblr, no Instagram, no Discord, or anything like that, so the only way you could really connect with other people was through fan forums.
I still remember MC being the only forum out there where I felt I really fit in with everybody else, which is why before TA joined and coaxed us all out of our shells, I really was far more elusive and shy around here. Prior to MC, I belonged to a few other forums, one of which was the old ToonZone forums, and they really had a lot of condescending people over there who liked to make you feel like a retard over petty little things. I also belonged to a forum specifically for COURAGE THE COWARDLY DOG, but it was a really small forum, and it was more like an old-fashioned discussion group (like Yahoo! used to have) rather than a community forum. And, of course, IMDb, but, well, we all know how that turned out.
I think this is why MC will never, ever have that true sense of tight-knit, close community again. There's too many other options out there and ways of connecting with other people that share your interests, it's a wonder that any forums at all are still alive and functioning out there. Plus, I think it's also generation as well: the current generation doesn't know what it's like to not have social media, and forums were the only way of connecting back then.