First,
There are multiple reasons this is happening. First, the Affordable Care Act (ACA) sets minimum standards for benefits, including mental-health and substance-abuse treatment, maternity care, prescription drugs, and rehabilitative care, which were not included in many of the old plans.


Second,
Some Democrats did care (notably Nancy Pelosi). Under her leadership the House passed a bill containing a Public Option. Unfortunately, the head democrat-wall-street-lacky in charge was the type of democrat you describe.