Delete your cookies for lemmy.world
Nobody wants to work anymore >:(
Is the only source for the jet part the tweet from the guy with "I will not submit. I will not comply." as his bio?
There's the default setting of your instance and then there's your own selection in your settings which overrides the instances' theme (unless you leave it on the 'Browser Default' option)
You can track a user's "karma" ie. total upvotes on posts or comments using the API but I don't think there's anything that allows threshold outside of creating your own modbot that would delete all new user's posts if they don't meet the requirement.
As for the purpose of the upvote I think it just functions as a 'I want to give this post/comment a boost' whether that be because you found informative, it's something that already agree with or is just a good contribution to the discussion.
A fantastic franchise if you like traditional turn based RPGs and the Dragon Ball artstyle.
It's neither instance's or the recent event's fault. It's been that way for a while now and is just a Lemmy problem that is being worked on. It has improved since the last month though so you're probably seeing the older posts that didn't replicate at the time. It was basically giving up too quickly when looking for posts from other instances which caused a lot of mismatch between what local communities showed and what it looked like on federated instances.
More details here: https://github.com/LemmyNet/lemmy/issues/3101
If you set registration mode to requires application you can preface the application questionnaire with:
** CHECK YOUR SPAM FOLDER FOR AN EMAIL ** We can’t accept you until you have verified your email address.
But at the cost of having to manually approve each user.
You need to reach out to the instance admins then