It's been interesting to watch the big RPG forums following the same trajectory over the years.
Back when D&D 3E was coming out, there were a bunch of forums active, but the big names were already RPG.net and ENWorld (Dragonsfoot, among others, being the torch bearer for grognards), while things like the SWRPG forum were HUGE repositories of knowledge about specific games.
At that time, both of the big forums were actually pretty open, and the only real limitation on language was Eric's Grandma's rule (no heavy cursing in order to not upset the hypothetical old woman). ENWorld became the leading forum for those that wanted 3E news and discussion, and RPG.net positioned itself as more or less the "anti-D20" boards. Nothing serious, just a slight holier-than-thou attitude towards those that enjoyed WotC's new system.
Then, over time, RPG.net started morphing into what became TBP. Censorship of language started happening, then certain views started being frowned upon, then bannings and now a full-on fucking dictatorship with ironclad rules banning even the mention of the existence of certain ideas/RPGs.
With ENWorld, there was a much slower progression, but things did start to tighten up. When Morrus took over for good he created Circvs Maximvs as a no-holds-barred alternative to ENWorld, for those that were starting to chafe under the new rules (mostly unwritten). That situation lasted for a long while, with people that felt uncomfortable at ENWorld migrating to CM, or cross-posting with softer language on the mother forums.
However, inexorably, change came, and ENWorld started resembling TBP more and more. CM eventually fell into disrepair (not even sure if it's still up) and ENWorld introduced more rules, written down this time around, and the mods started policing discussions in a far harsher way than before.
Nowadays, I think there's still a difference between the two of them, with TBP remaining a much worse place, with draconian rules and summary bannings that would make even some of ENWorld's mods blanch.
A sad story indeed.