Why do local authorities challenge the established science published in JAMA that healthy individuals should not wear facemasks?

It would be nice if it could be how you are suggesting but the dilemma is that people who should wear face masks can't be trusted to wear them, so the only safe solution is to require everyone to wear them.  It does suck that the good have to suffer with the bad.  Hopefully, it won't last long.  

Infected individuals should, though, and without testing we cannot know if we are or not.