please just check the block data to correct yourself.. you dont need to believe me.. nor falsely TRUST the cult stupid brigade, but simply check the blockdata

in 2017 there was a NYA agreement to mandate the banning of blocks that used old version numbers.. whereby pools and economic nodes would only accept the new block versions to signal a move to segwit, and strip the block data to old nodes that would not understand segwit that segwit nodes of economic nodes and pols were part of..  
you can check this using real data of code and blockdata.. not human trust..
the blocks that had old versionbits ended up being BCH. and segwit via the mandated NYA policy only accepted the new version bit blocks by banning peers that tried to send old style blocks. thus causing a divergence of nodes..
it was actually gmaxwell that then pleaded to the bch crowd to change to not cause setwit nodes to keep needing to ban older nodes to formalise the separation..

the mandatory block selection which you can see was a unnatural(via mandatory banning old versionbit marked blocks) incline to 100% reading of block versions to make it feel like the network wanted to 100% move to segwit to an unnatural(via banning old block version) acceptance of segwit

so when old nodes using code before 0.12 would accept old versionbit blocks. it did cause a split.. but it did not require old nodes to adjust code to do so. old nodes accepting old blocks did not need to change code to cause a fork.. the fork ocured due to segwits block selection(rejection)

emphasis the code adjustment between the block types was actually initially caused by the segwit side of nodes. and banning peers that tried to push old blocks to segwit accepting nodes.. and then segwit nodes would strip the blocks to remove witness to then filter stripped blocks to their peers that didnt understand segwit(aka backward compatibility)..

so check the code check the blockdata. and acquaint yourself with fact not the fiction via the idiot brigade.. dont fall int the trap of the silly stupidity you followed years ago.

bch didnt decide to create an altcoin but tweaking code to cause a differential of different block type.

im saying this to correct fact, and no it does not mean i wanted nor was a bch-er i just prefer facts over fictions of versions of events of who caused what first