The only reason you would ever be worried about receiving "bad" coins would be because of some legal framework that makes such coins possibility "bad". The exact same legal framework could make 100% of Monero's coins "bad". And you're back to square one.
My understanding of your argument is that in order to maintain fungibility, you need privacy or else that fungibility will be attacked. My argument is both a private and a non-private coin can be equally attacked, and in that situation both can be equally used outside the legal framework (i.e. Bitcoin and Monero will both still process "bad" coins with no discrimination) with fungibility untouched.
man that's some mental gymnastic you do, the math is simple, Bitcoin is not inherently fungible but no one is saying it is not or cannot be used as money because of what, you are free to keep using 1984-tokens in your future.