Earlier quoted context omitted.
It's confusing for me that so many people will complain about how the police unions prevent reform and allow for bad behavior -- but then support unions for all other public sector workers.
It's a balancing act. With no unions, employers can stomp all over their employees, and everyone is worse for it (e.g. Amazon). When the unions are too powerful, they can stomp all over their employer and everyone is worse for it (e.g. police unions). Like all things in life, nothing is cut and dry. It's not wrong to both support unions, and call for the reduction in power of police unions.
Public sector unions "bosses" are the people and politicians, so even though these are "private" unions, their alignment is to protect the political class first, cops (members) second, people third. By focusing on politic over people (bad looking cops = lost mayor, DA political race) their primary interested is not public transparency (where the money comes from, leading to lack of consumer alignment on service rendered b/c cops are serving political interests more than they should).
In a private union, the first people they are protecting are their membership (lot could be said here about how that works in practice), but their transparency problem isn't regarding factory deaths or issues at the work place because that is precisely what they are created to bring awareness to. If Ford's cars are killing people, the union actually wants to bring that up since it can hurt employment opportunities for future members.