It is a matter of responsibility. If you can log into any lemmy instance or mastodon server with the same account, then which server takes responsibility for your actions in the fediverse?

I have seen instances be defederate from because of their lax account creation requirements, or because of harrasment from users from a specific instance.

If an account can log into any instance, then who is responsible for banning the account?

1. It reduces the barrier of entry for new users to get an account going that is not flooded by political extremist views in it’s feed.
2. It causes anonymous users to not see they shitshow. And since most users start out by browsing anonymously while deciding whether they want an account or not, that is a big deal.
3. It gives the impression that this community is at least somewhat ok with the views that these extremists hold.

It should be opt-in to view posts and comments from these sources.

Should a dedicated search not use/index ActivityPub instead of the html interface?

If so, instances can simply defederate from search engine instances. So the point you are trying to make still holds.

1. Threads federates
2. Threads hosts 99% of all content and all users.
3. Threads releases and update that allows a new feature. Example: they add buyable threads gold, that you can reward to a post or comment.
4. The rest of the fediverse can’t implement this feature, and is inherently left behind in terms of features.
5. Threads releases an update that breaks federation. 99% of the users do not notice.
6. It takes Threads 3 months to fix the issue.
7. Go back to step 5.

Every non-Threads participant will have less features, and is constantly struggling to keep up with the changes and bugs of Threads. Result: the fediverse cannot grow. Only the most stubborn anti-Meta users will accept the objectively worse experience, just to avoid using Threads. But the average user will just use Threads, instead of joining Mastodon, Kbin, Lemmy, or any of the many other fediverse instances that Threads can federate with.

New users will look at lemmy.world before they create an account. They will choose to join after seeing threads posts and comments on the front page. The default settings will keep them looking at threads untill they figure out they can block it. But when they do, they realise that 90% of all posts and comments came from threads, and they just disabled most of the content.

I would be ok with an opt-in mechanism, where the default settings and the anonymous settings disable threads content, but you can unblock them.

People always need something to complain about. If the icon and position of the submit button is the worst they come with, they are probably pretty happy.