In short BCN have described the origins of BCN stemming from cooperating groups on the darknets. The is coroborated by the Cryptonote Team. Monero asks for evidence and proof which (unsurprisingly to me) are not provided* given the secretive nature/origins/development of this coin. Contrary to Monero thinking the absence of evidence is not (in this case) evidence of absence.
It is not Monero who asks for evidence, I am not a Monero holder and would also like to see some evidence to support their arguments. Moreover, I am absolutely sure that most Bytecoin holders would also like to see some kind of evidence.
As long as they don't provide any evidence, the people behind CN/BCN should not be trusted.