I've always felt that worker unions should be treated a bit more like a hiring firm or even one of the old guilds.
To wit: If the workers decide that they want to organize and be treated as one unit, more or less, they can do so. You can also chose to fire the union, which means firing all the workers in the union, but oh well.
The potential of losing a substantial part of their work force should keep the businesses honest, it to being a nuclear option.
Unions should understand that the nuclear option exists, and act accordingly.
I believe a lot of the hate for unions in the USA is because the unions in the USA are too powerful, too disruptive. There's lots of unions in other countries, but they are restrained better. Ergo, actually beneficial to the business. For example, in many European countries, they take care of the worker's pensions and medical benefits. The business doesn't have to worry about it. Bonus.