I'd disagree with that, on all levels.
An educated workforce is the best thing to happen to the country since the industrial age. An educated workforce also knows what it took to train them for their job, and knows that compensation should be comparative to the funds used to train the skills. If any employer decided to undercut their staffs compensation on a whim like you suggest then they would lose their staff entirely, to another employer willing to pay employee's what they think they are work, up to the point that sector of the economy can handle.
Additionally if an entire industry decided to undercut it's workforce in such a way, collectively, then you would just push your employee's (again educated workforce) into entrepreneurship, creating new competition for the skilled members of that workforce.
Honestly consider if you have a business employing say 50 technicians currently making $25 a hour, which the business now says will only pay them $1 an hour because they don't want to pay them that much anymore. What will those technicians do, honestly? Leave for a competitor for better wages, create a new business and take as many of their customers with them as they can or take the skill set and apply it to a new industry. All the business owner did was kill his own business in one policy move. That is not to even mention any litigation that might ensue by the employee's after they leave. Take technician and replace it by any other skilled laborer, and the same things will happen.
Also if unions disappeared, we'd still have federal and state level regulations requiring certain levels of compensation.
Sorry, what you suggest doesn't pass the logic test.