But if as a low-level manager I can gain sympathy and build relationships with my superiors by blaming my inefficiency on the union-devils, why not cause a petty delay with passive aggressive rules.
The union might be a corrupt and self serving enterprise. They may just be reacting to abuses by management.
Perhaps the company kept getting fines from the fire marshal for unsafe use of extension cords. Management tries to use that as an excuse to harass or fire their electrical workers. The union responds by saying that their electricians never saw nor approved the use of the cords and that they had no way of knowing they were in use. After enough hostile interaction, you wind up with a rule that nobody can plug their own computer into an existing outlet.
The places where I hear about the worst red tape, are places where the relationship between the unions and management are really antagonistic. Both sides need to remember that everyone wants the employer to be successful, because then there are more profits for everyone to share.