[hoaw]

No they can't. Talented people have years invested in products, projects and relationships at a company. That is why you see "after 10 years at x, head of y is now leaving for z". It is average employees that can switch without consequence since they don't have a position.

Say you are a talented employee at company X. You have invested time and effort in a project for the last three years and done good work. Now you get into a dispute with a manager over the future of the project. They start playing office politics and eventually get your project defunded, blocks your promotion and requires you to sign a non-compete to get your bonus.

While you can just quit and join company Y the first thing they will ask is what you did the last three years, what your project was and which position you attained. Chances are you are back in a similar position, having to reinvest that time and effort. Thing like this can really mess up your career.

If you are just working on a average project, not really expecting a promotion or in other ways are average, you don't have as much to lose. Sure, if you don't get treated right at company X, you go join company Y in a similar position. On the other hand since you don't expect a trajectory attaining things like good pension, vacation and overtime early matters a lot.

[sublupo]

You are right, it would have been correct for my comment to refer to mid level people. But regardless, creating minimum wage would not help you unless you are the type of person who would earn below "union minimum wage" without the union. Otherwise, you would be diverting part of your paycheck to low level employees and to union fees.