The instance seems to be mostly right wing trolls. I know defederating is unpopular but I don't think much is to be lost in this case and it can save the mods some headaches.
Edit: the response on exploding-heads.com to my reporting of transphobia. Courtesy of the "second in command"
You don't see their communities unless you subscribe. If their users are posting in our communities and breaking the rules of the communities then their posts will be deleted and the users banned.
There are moderation options other than de-federation. De-federation is an option of last resort to protect the greater community from violence, abuse and crime. De-federation is not a tool for sending a political message.
You can personally block that entire server and you will never see anything from them.
My username shows @Difficult_Bit_1339 to you, so we're on the same instance. If it had @lemmy.world then I would be a user on the lemmy.world instance.
If you choose 'All' instead of 'Local' or 'Subscribed' then you see everything that exists, yes. I wouldn't recommend that since it is an incredibly spammy experience. That being said, you can block any community like so: