I am still somewhat new to Lemmy, so maybe there is some history with Hexbear that I am ignorant of

Hexbear is a 4 year old community, it drastically predates the Reddit Exodus, and only started federating with other instances around 10 months ago. Those 3 years of self-sustainability created a unique culture that is at odds with the liberal instances on Lemmy, like Lemmy.world.

I would defend anyone's right to be different as well. However, that's not the case here - you said it yourself, you really are missing a huge history between Hexbear.net and... well, everyone else across the Fediverse (and highly ironically, as such they would ruthlessly make fun of you, for speaking without knowing - i.e. you are someone who would defend them, but not vice versa). They poke fun at liberals, conservatives, anyone from the West, etc., and the issue isn't so much their right to exist or be different, but the need for the rest of the Fediverse to spread their message out in the same manner as all the other messages, which are governed by an entirely different set of policies and code of conduct.

I hope you will agree with me that the rights to do a school shooting, or the right to block someone else's access to medical care... is really no "right" at all. That is to say that they can be however they like, but the moment that they federate with the rest of the world, it crosses over into our rights, whether we want to receive what they offer or not, and even more so to promote & share it to our own users.

But don't take my word for it: visit e.g. ChapoTrapHouse or the_dunk_tank and see for yourself. Or here's an example post, where they took a poll on which other instances to deferate from, then promptly ignored the results that said no and defederated from them anyway:-P lemm.ee for instance had 41 votes to keep it and only 4 for it to go, but despite the additional order of magnitude and some passionate responses defending the former (e.g. "But man we should at least stay federated with lemm.ee, that instance's admin has been very reasonable and it hasn't caused much trouble at all; nothing that banning any troublemakers can't fix."), they defederated from it anyway. And the reasons stated to keep it are also informative - basically so that they can proselytize to them, though notice the distinct lack of wanting to converse with them as equals. And that is just one instance, among the very few that will even consider federation with hexbear.net to begin with. Also, to balance that out, read lemm.ee's policy on federation with hexbear.net - notice how 100% polar opposite it is, not just in terms of facts but of behaviors.

There is also programming.dev's response, tldr version: "Hexbear defederated from us so to prevent one way conversations I have added them to our blocklist as well. If the hexbear admins decide to unblock us I can do the same"... followed in the very next post by "It is very likely we will be federating with Hexbear again..." - which despite the fact that that did not end up happening (as of September 8, 2024 I can see hexbear.net on their instances list, make sure to switch the tab at the top to "Blocked Instances"), I want to point out how extremely friendly other instance admins continue to try to be, towards them, though this behavior seems to have never been rewarded in return. And it's not just these two instances - there are so very many, here's another at sh.itjust.works, where they thought long & hard about it (mind you this is an EXTREMELY permissive server, chock-full of reasonable-minded people, which you'll see as/if you read the other posts in that community), and somewhat shockingly seemed ready to do the defederation, but before they could, once again hexbear.net preemptively did it first, thus making the issue moot.

In short, they know exactly how they are - and many people routinely flee from it to spread elsewhere in an attempt to get away from the extremely heavy-handed authoritarian moderation/admin practices. When you tolerate the intolerant though...

If you enjoy LGBTQIA+ content, it is everywhere, e.g. the variety of blahaj's that exist - the most popular of which is https://lemmy.blahaj.zone/, with the highest number of users (and to reveal my own bias, I've never seen anything written from their admin, Ada, that I have not thoroughly enjoyed reading - if I could follow accounts on the Fediverse, this is one of a mere handful of people across the entire world that I think I would do that for:-). Similarly with "different"/odd content - we love being different here on the Fediverse:-) - and again with left-leaning content (in fact people that are not left-leaning are quite rare).

But I advise to steer well clear of bigots. Except of course to learn about the situation - definitely check it out, and then you'll know. I know it looks like shit-posting, especially with the rather poor choice of wording in OP's title, but there truly is an actual history behind all of this. The shit-talking looks casual, but it's not: hexbear has truly earned most of the ire that is directed its way. And they seem okay with that, some even seem proud of it? :-P