Is the result that many young people will not enroll and use private plans instead? As people age it would then make sense to enroll, but will the system be successful without the young (young including healthy)?
Whether you sign up for coverage through an employer, or on healthcare.gov, or ehealthinsurance.com, or an insurer's own website, it's the same companies providing health insurance today as 10 years ago. "The system" includes everyone with insurance no matter what channel they used to sign up for it. The ACA or the healthcare.gov marketplace aren't a separate system that needs its own enrollment numbers to work, AFAIK at least.
