It kind of makes me think of how odd it would have been if many of the old forums named themselves like bookclub.phpbulletin.com, metalheads.vbulletin.net, or something.
There’s nothing wrong with doing that, obviously, but it’s struck me as another interesting quirk of fediverse instances/sites. Generally as soon as you visit them you can tell by the site interface or an icon somewhere what software they’re using.
Because Lemmy is bigger than one domain. If it were just one domain it would be Lemmy.com, but since it’s federated, the names must be different, but you still want people to know it’s a Lemmy instance because they all interoprate.
“Hmm, what’s bajesus.com? Oh, its a Lemmy instance. What’s lemmy.bajesus.com? A Lemmy instance, of course.”
Lemmy is a technology where each instance follows the same rules: a compatible federation API. You want people to know your website is a Lemmy instance.
A bulletin board might one day change to entirely different back-end and migrate all of the posts and users. That’s highly unlikely you’re going to do that with a Lemmy instance. It will always be a Lemmy instance or it will go away. You’re not going to migrate the content and users to some other technology. And even if you did, you can buy a second domain easy peasy!
I kind of see where you’re coming from, and I think the reason I wasn’t thinking of it in those terms is that I see ActivityPub as the more important underlying tech across the fediverse than say Lemmy/Mastodon/Friendica/etc.
I say that in part as I’ve come into the fediverse from Mastodon, where there’s more than two options in play, e.g. Akkoma/Firefish/Misskey/Pleroma/etc. each of which has some commonalities, but also some pretty distinctive features, particularly from the Misskey side. Hell, Mastodon itself even has Glitchsoc, which is what the original instance I joined on that side of things runs.
On reflection, I don’t know that the microblogging instances mix in the name of the software they’re using as much, which you’d think with more options they might be inclined to, but the more I think of it the more I remember a lot of them use some fun, odd names instead.
Also the practice of using a subdomain to indicate which program is running is pretty old. That’s what the www subdomain on so many websites is.