When r/Bitcoin moderators began censoring content and banning users they disagreed with, r/btc became a community for free and open crypto discussion. This happened long before the creation of Bitcoin Cash. Today, r/btc users can discuss any Bitcoin-related topic without fear of moderator retaliation, while r/Bitcoin and r/CryptoCurrency are still heavily censored.
Over the years /r/btc became community of historians & torchbearers, preservers of Satoshi's Bitcoin for future generations.