Why?
Well, first, I'm assuming the nature of that subreddit is self-evident, obviously. I'd never heard of it. The larger idea is that modern intellectuals have decided censorship is automatically a bad thing, and I disagree. Some ideas deserve nothing but. I do not consider the concomitant slippery slope rebuttal logical, before you raise it. Never have.
This seems naive at best. Obesity carries with it increased health risks leading to overall higher medical costs for everyone. Second, "I do not agree with what you have to say, but I'll defend to the death your right to say it." is a concern stone of Western Civilization, iirc.
Please don't give me flack based on me knowing, but the guys and girls on /r/fatpeoplehate often talked about not only the increased medical costs, but a lot of the issues that were had were things such as nursing staff and EMS employees being physically injured and unable to work due to having to move/lift obese people. Also there were many people who were upset by people who they worked with stealing lunches, being obnoxious about eating, or being rude seeing that they weren't "eating a man's lunch". It's easy to see /r/fatpeoplehate as its name, and at its core, it is just a hate sub. But anyone who looked through the comments would see people who are frustrated and just need a place to unload, and it was by far the most tolerant sub I've seen. Didn't matter if you were gay, trans, muslim, or any minority. As long as you weren't fat, you were seen as not just another person, but as brethren. You were also a shitlord. What I'm trying to say is that most people seem to think if you were to subtract the fat people from /r/fatpeoplehate it would just be an angry group of trolls looking for something else to be angry and hateful about, but at least from my experience, it was a safe-haven where everybody was truly equal, and everyone was valued.
I don't have anything specific to say about the subreddit. I never visited it and have no experience. However, I do find it a sad fact about human nature that we can bond so strongly around opposition to another group of people, which can be defined in almost any arbitrary way, as long as a commonality of negative opinion can be reached.
All human bonding is based on an arbitrarily common opinion. I highly doubt you have any friends who you disagree on everything with after all. I personally have most of my friends and bonds come from the queer community in my city. It's completely arbitrary and says little about our personality, but it's a commonality we could bond because of. We share the opinion of anti-queer people being bad people, and that's why we bonded. Not only can we strongly bond around opposition, we are required to bond around opposition. What I'm saying now is all conjecture and not on any level of research, but if you think about pre-historic days, it makes sense that we would all bond when a problem arises, that way we as a group can fix the problem, and it's a boost to morale knowing others have the same opinion. It just so happens that the biggest threat to today's society is arguably the obesity epidemic which is overtaking smoking in it's death toll. If instead, say, windows were a huge issue in society killing more and more people every year, chances are I'd be over on /r/glasspanehate or some similarly named subreddit. That being said, I cannot hide the fact that /r/fatpeoplehate was a hate subreddit. It had people there specifically to stir up shit. There were people who were overtly hateful, brigading people, wishing them death on their social media, etc. I am not proud of this, nor did I or any of the mods condone this behaviour. It was however the exception, not the rule.
This is pretty much spot on from what I experienced. Despite the name, it wasn't just filled with, "hey, look at this fat person, fuck them. " It was mostly directed at other people's obesity/fat promoting causing issues for others - taking up multiple bus seats, convincing people to give up on diets with pseudo facts, encouraging obesity. There wasn't hate for larger people in general, just hate for fat people that felt their weight gave them a right to act entitled and pretend there was absolutely no way they could change their situation.
When you say
Tolerance, adjective, "showing willingness to allow the existence of opinions or behavior that one does not necessarily agree with." Their rules said
it was by far the most tolerant sub I've seen. [..] As long as you weren't fat
So not tolerant at all. No dissent / No being fat
Absolutely NO FAT SYMPATHY