Since when did insurance companies become 'THE' solution for all of the health care issues?

It seems in the past an insurance company role was to assess risk and based on the results, established policy coverage terms, set prices and issue policies. This resulted in the insurance company receiving premiums and making payments, as required, to the policy holder. Insurance companies weren't seen as 'the' most important player in 'minimizing' the policy holder risks....nope...the policy holder was held accountable for minimizing risk.

Today the health care discussions are focused on what is wrong with health insurance companies. These companies are, and should be, criticized for their policies on 'pre-existing conditions' and always pushing back on claims before making payments. I also wonder when they became the experts on our health care experience so that we hold them responsible for correcting the inefficiencies? It is bewildering to me how they ended up in this role and whether they should have the role, I think not. Heck, when it come to health care reform I'd just like to get a consolidated bill from the labs, doctors, technicians etc. for diagnosis and treatment for a health issue.