For me it's the sort of thing I looked for for a long time.
I'm in other hobbies, and there are boards and mailing lists for those too, but only a couple I really like.
As far as cards go this feels more like when I started hanging around a card shop in high school. The owners knew a lot, and some of the customers knew more about some areas, and hanging out talking about cards or baseball or any sport sometimes even non-sports was totally ok. A great education about what was a fringe hobby at the time.
Later on, it got so there were shops everywhere, most run by guys who only knew what was in Beckett. The smart ones sold around 91-92, the rest took a big hit with the strike. The rise of the internet took out the ones who couldn't figure out how to use it. All that led to a sort of "scratch ticket" mentality, and not much interest in anything older than a couple weeks. Nearly no technical knowledge, not even an ability to ID a less known set. (Never mind figuring out M101s or anything like that) It was literally a hobby that never grew up.
For me 96-09 was a period of relative inactivity. I still collected, but went to fewer shows and focused on other stuff. I helped go through a collection in 09 and found information about a few cards I'd never seen before over on the NS side. And finally checked out this side. And it felt like home. Even really obscure topics like unlisted varieties of modern sets got some respect. At worst an online version of the blank stare I was used to, without the obligatory derision follow up. (Ok, sometimes but typically a polite silence if the subject is one that bores people into a coma)
And some of the posters are people who I'd never met, but knew their names from ads etc.
Pretty cool.
I think my intro to the harsher side was mentioning I had some blank back T206s and basically getting a polite "put up or shut up" - Posted scans and all was well.
Yeah, this can be a harsh crowd, but in some cases it needs to be.
Steve B