Honestly, I end up arguing a
LOT with people who are gung-ho for single payer or other UHC solutions. Not because I'm against it... but because their arguments are so naive and well... I really chafe at blind dogma. Personally, I fully agree that a universal coverage solution would be preferable. If I were the queen of the world, we'd have had something worlds different from what we've got now. But reality exists, and we
do have something... and changing it means
disruption... and disruption means that people end up unemployed, they lose their homes and their livelihood, they go bankrupt, and they end up all around screwed all because someone is trying to do something for the greater good,
and that greater good didn't include them 
.
The health insurance industry that we have, in all its glorious mess, is a tenacious weed that accounts for
more than 15% of our GDP. I don't even know how many people are employed in the health sector - hundreds of thousands? When the rest of the developed world looked around and said "Gee, I think we ought to share the burden among ourselves for this one", we took a different path. Part of it is our national contrariness, sure... but some of it was responses to the pressures of the times - hiring freezes and economic pressures that prompted employers to find creative ways to compete for employees led to the integration of medical insurance into employee benefits. That more than anything has led to our current situation. Hindsight is 20/20 of course, but if medical insurance had never become an employee benefit, then I doubt the private industry would ever have grown as large as it has - the cost to the consumer would have been more apparent and immediate, the bankruptcies would have been more abundant, and our government would have responded before the industry had grown so many roots.
As it is, we have an industry that is fully intertwined. It's like a giant Jenga tower, carefully balanced. You can't just yank out the block marked "Private Insurance" without toppling many others. In some states, private insurers provide the entirety of the medicaid services through managed medicaid programs. There are immediate impacts to the employees of those insurance companies, of course, but also to insurance agents and brokers, as well as consultants, and insurance regulators. There are impacts to drug companies, hospitals, pharmacies, physical therapists. It's a mess.
So while I'm philosophically and principally supportive of a single payer approach, I'm hesitant to rush forward too quickly. And I'm particularly skeptical of anyone who approaches the topic with torches and pitchforks raised - I look askance at anyone who seems to say "I want single payer, and I don't care how many people I have to kill to get it!". That seems to be entirely too contradictory to me.