I somewhat agree, I actually don't think vitor is doing what you are describing and I also don't think it is merely an amethyst problem (again I am speaking from a place of confusion lolol).
There are a couple things. There's the spamfilter system, which seems mostly fine just occasionally faulty.
But really I'm speaking about the blocking system. Which is not just on amethyst but seemingly on all clients (?). Where if 5 or more accounts you follow block a user. That user is blocked for you.
I'm just thinking that this is creating a shadowban list, which isn't much of a problem now. But perhaps moreso as nostr grows(?) You have a handful of 'must follow' mega-followed accounts and whatever accounts you follow. It's not very hard to see how someone saying something unpopular will make it onto a v widespread blocklist.
Again I am confused by all this..this is just my reading.
If you were to see this on BlueSky would you not call this a shadowban? No meant to sound rude btw. Just out of curiosity...?