Kidnappings (and pretty much any crime imaginable) would happen a lot more if everyone listened to the advise of never talking to the police.
People can protect themselves from police oversteps without listening to extreme advise from someone suggesting we pretend we don't live in a society.
I'd think any reasonable advise would consider the probability that talking to police in any particular scenario would lead to bad outcomes vs good outcomes, but maybe that's not catchy enough to be retweeted on social networks.
Two recent episodes of the "Criminal" podcast [0] documented that it's a bad idea for even victims of kidnapping to report to police. In this case, it wasn't because the kidnappers punished the victims for reporting, but because the police themselves harmed the victims.
My impression is that cops are incentivized to close the case much more than they are to find the truth, and the most prominent targets of their investigation will be friends, acquaintances, and family members, so even in the unlikely case of a loved one being kidnapped you should be very careful and probably talk to them only through a lawyer.
The real fool in that story was the Fed brother. How could an FBI agent really believe that running to the local cops was the best thing to do first? That is a complete misunderstanding of every aspect of USA criminal justice system. I don't know how that guy avoids getting drummed out of the bureau after this podcast.
How often do you think this happens? How often do you think police overstepping their limitations happens?