By and large unions focus on pay and conditions, not corporate direction.
Insofar as unions do anything political it is usually inappropriate and better done through actual regulation so all companies obey in a coordinated fashion.
Hard disagree. A union is there solely to give employees a proper voice at the company. That this has by and large been to support working conditions historically is only because it was the issue of highest importance.
If the concern is corporate direction, the union has a seat at the table as well.