I think the article approaches the story from a particular vantage point. But for me personally, as freelancer and a substantial earner, I tend to not identify with the idea that we are part and parcel abused. It may be what I came from (poor farm family) that gives me a different perspective. But I have found corporate America to be fairly generous, you just have to ask. Which brings me to the above quote, while I do belive employers utilize independent contractors in some instances to cut cost, what I have found in many of the situations I have been in, is that it is a tool used to identify cost up front and to mitigate risk, usually companies are willing to pay a small uptick in cost to reduce a huge downsize risk and employees and employes health both represent substantial risks to a company.
I think where we as individuals go wrong is in charging rates similar to those of employees and then taking on the risk the companies does not want to shoulder on top of it. When the reality is, we should be asking to be compensated for that risk (just as insurance companies are) and we should be willing to walk away from a company that unreasonably expects up to take on their downside bet with no upside of our own.
What I don't believe that high earning potential people need is collective bargaining. That being said, what the article discusses sounds like they are more of a health care co-op than a employment union bargaining with employers and I am all for that. Health care co-ops help us offload that risk onto a proper entity, employers where never really the correct entity to deal with that risk in the first place.