If this is a major concern for a mastodon user, they will need to either host their own instance or find an instance with as lax moderation policies as possible (and deal with the risk that other interests could interpret that as toxic and ban the whole instance).
But I agree with the model Mastodon is building out over the model of centralization that Twitter had. I think Twitter encouraged too much topic-free shouting into the void, which decreased the utility of discourse in general.
It's also really unclear to me where the OP is getting the sense that Mastodon instances are so heavily topic-oriented. I haven't observed any stories of Mastodon admins blocking users for being off-topic; the flavor of sites seems to be more about shared interests in the sense of old IRC communities than in the sense of topicality like a subreddit.
But I agree with the model Mastodon is building out over the model of centralization that Twitter had. I think Twitter encouraged too much topic-free shouting into the void, which decreased the utility of discourse in general.
It's also really unclear to me where the OP is getting the sense that Mastodon instances are so heavily topic-oriented. I haven't observed any stories of Mastodon admins blocking users for being off-topic; the flavor of sites seems to be more about shared interests in the sense of old IRC communities than in the sense of topicality like a subreddit.