Yes. BNBR is not an obvious notion to people who have commented to any significant extent on the Internet, and the requirement for BNBR is something users stumble on, not something they’re particularly alerted to. Quora’s particular notion of BNBR is far less intuitive than many are assuming it is: the tone policing, the expectation of deference towards public figures, the intolerance of several forms of humour.
Answerers are getting sidetracked into mechanisms of how the onboarding should be done, or how difficult it would be to ensure that people pay attention to onboarding. I would still retort that some onboarding is better than no onboarding, and no onboarding has been Quora’s MO for years now.