Perhaps it is that many people assigned unions and government at-large the role of 'good guys', with corporations and criminals being the 'bad guys'?
In any case, most libertarians (such as myself) have been skeptical of the police and unions (especially public-sector) for a very long time. We've been talking about these issues for decades, and wondering why nobody else noticed what was going on with the militarization and lack of accountability of police. I suppose we finally have our answer.