[Johnny B.]

I meant “One doesn’t”, but I always thought that sounded pretentious, so I substituted “You don’t” without thinking you might reasonably take it as addressed specifically to you. :-)

[Mycroft Holmes]

I meant “One doesn’t”, but I always thought that sounded pretentious, so I substituted “You don’t”

And that is what "one" is for. A lack in standard English that is addressed by the Southern "y'all" is another, more specific pronoun that needs greater currency.