Sure, but phpBB boards are separate entities, not parts of a whole… So that’s not really a 1 to 1 comparison, IMO.
That being said, you’re right. If people started sharing instances directly instead of just saying “Mastodon,” this issue would be attenuated, at the very least.
The issue is that people want the social part of social media. If you share mastodon.social, people will think “Mastodon,” but if you share indieweb.social people will be confused, and possible disinterested because they don’t necessarily expect to be connected to the other “Mastodons.” At the end of the day, you’ll always have to say it’s a “Mastodon Server,” and as soon as that gets brought up, I’m afraid it might push people away before they even get a foot in.
Then again, that’s kind of how Discord gets shared around, so maybe that’s OK, IDK.
100%!