Other fediverse microblogging platforms all have blockers to broader adoption -- functionality isn't fully there yet, horrible UI, not a lot of support from hosting companies, etc. And with most of them, support for controlling federation choices isn't much better. So things are trapped in this weird suboptimal state; and most microblogging resources go to Mastodon, so it's been hard to break out of the cycle.
And there's historically a LOT of resistance in the fediverse to consent-based federation. @anildash talks about how consent's a key often-unstated value in the fediverse, and that's true, but in practice it's also very intermittent. And many (most?) high-profile fediverse "influencers" are in the camp that's actively hostile to consent. So incremental change is hard.
@polotek @tillshadeisgone