Why are you saying this? It's what every single corporate pamphlet and forced talk says. No one is saying unions will bring everyone enlightenment and cure cancer.
What people are saying is workers need a say in how the workplace is run and companies spending millions convincing folk otherwise should be forced to stop.
Few people are able to view unions objectively instead of picking a side, a union comes with tradeoffs not universal goods or evils. There are plenty of examples of unions fixing things and plenty examples of them making things worse, your opinion of a union shouldn't be based on keeping score but actually looking at the risks and rewards. Unless an organization is particularly nice, unions make a lot of sense for low skill, high turnover jobs in large corporations; unless a organization is particularly bad, unions don't make sense in high skill professional positions.
What people are saying is workers need a say in how the workplace is run and companies spending millions convincing folk otherwise should be forced to stop.