If the argument is, some [government] functions are too critical to public safety to put in private hands, then that is an argument against allowing them to be unionized. If unionized, then the state no longer has a monopoly on the power exercised by that arm, which is the whole idea of putting it in the public sphere. So if you can't have private police forces running around, let's say, then it makes no sense to have the monopolized force of the state colonized or even dominated by a union with interests frequently opposed to those of the public.Some people in NYC died because the snow prevented public safety personnel from getting to them. The Snow Plowers Union didn't think about that one way or the other.
Why should they? The interests of public-sector unions are necessarily not congruent with the public interest. Even FDR opposed unionization of government employees, because of the moral hazard involved.
That, of course, is the problem Mr. Smith brilliantly and succinctly points out. It applies equally well to the arguments of teachers' unions. Simply change the words "public safety" to "public education."
You go, Governor Walker. Stay the course. Governor Snyder can use a moral example.