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 have to equally resort to being used outside the legal framework in order to maintain fungibility, so I don't see an advantage of one over the other.
When the law became unbearable in Rome, the people abandoned their land. Later there were cows grazing in the city of Rome. The population fell from 1.3 million to 30,000 in a waterfall collapse.
My thesis is as follows.
We are headed into a NWO tempest where there is no rule of law, only a rule of oblivious addicted masses and gestapo bankster coattail goons.
I long ago gave up on keeping the world we have now, with all our Walmarts, etc..
I am ready to move forward to the world where we sell downloadable 3D printer products anonymously for micropayments, etc..
Your old world will die a slow death of increasing totalitarianism over decades. It will waterfall into collapse 2018 - 2020, then the banksters will reset the global economy on the NWO reserve and institute an increasing level of totalitarian control over humanity in the old world contexts where they can. Over decades that economy will wither and destroy itself. The capital remaining in that old economy will wither and be destroyed within that system.
Realize that the mavericks who shape our world are usually scorned and rejected when they present radical visions of the future.
Add: that doesn't mean I give up hope on every individual in the world. I want to build out the future and those who avail of it will prosper. It is not my job to hold every person's hand and force them to choose. The gate to prosperity is narrow only because the people refuse, not because the opportunity is limited or restrictive.