powerful or powerless unions?

Some silliness over at Blue in the Bluegrass...

For the death of the security guard in the Holocaust Museum shooting, the writer blames Wackenhut (the company) fully, with no blame for the (powerless?) union and the workers. There had been discussions between the union and the company about bullet-proof vests, but at the end of the discussions, they had decided-- at least before the shooting-- that it wasn't worth it.

You already know that it is only thanks to unions that we have an 8-hour work day, a five-day work week, protections from dangerous work conditions, wages sufficient to support a family, benefits like health insurance, sick time and pensions.

But did you know that if Wackenhut had not been able to stall a union's demands for safety equipment, heroic security guard Stephen Johns might still be alive?

The same unions that (supposedly) were so powerful to do everything in the first paragraph were unable to get their workers in vests? (In fact, it's a longer story, but although one can claim that unions were responsible for some improvement in some workers' conditions back in the day, it requires amazing assumptions to imagine any such result today.)

Note that the cost of hiring a worker has various components-- and a firm would be perfectly happy to spend $X on wages as $X on an additional safety feature. The firm will respond-- especially to a union [labor market cartel]-- to provide what workers [or at least the union] wants.

For such an inexpensive item, why didn't the union sacrifice an infinitesimal percentage of worker compensation to get the vests? Either it wasn't that important to the workers &/or or to the union-- at least until the shooting.