So labelling all of Mastodon antisemitic or anything else speaks to a lack of understanding on behalf of the person making that claim.
There's no misunderstanding here. It's not some honest confusion. These people are fascists spreading lies. There's no point in preaching to them (or us) about the technical reality of Mastodon. They don't care about Mastodon. They don't care about reality. Their platform is based on denying reality.