> If mailing lists and newsgroups and BBSs and blogs with comment sections and instant messaging/chat rooms and forums and wikis are all "social media"
Yes, I would consider basically all of those things to be social media, with the possible exception of wikis and blogs where most people don't go to the blog specifically to comment and read others' comments. They are all media for social interaction.
On the other hand, news websites like bbc.co.uk or company websites like microsoft.com are not, generally speaking, social media.
I realise we can argue forever about the corners of this loose definition I haphazardly threw out. But what is the rationale for distinguishing between Reddit and HN (on the one side) and Twitter and Facebook (on the other)? The root comment of this thread complained about social media being full of marketing, PR, virtue signalling and self-promotion. You can argue that is an unduly harsh assessment, but BBS, IRC, Reddit and HN have all had their fair share of all that stuff.
> why did anyone invent the term "social media" 20 years after it had existed
Because back in the 90s the mainstream media had nothing to say about BBS and IRC so they didn't need a term for it.
