If insurers limit the physician supply in the exchanges, resulting in access problems and rationing, patients will simply stop signing up for the exchanges in the first place and simply pay the penalty/tax or forfeit any tax refund.
Only the very sick will sign up for anything because it will be a very bad deal for routine care and even chronic care. It will be difficult to force the healthy and those with less serious chronic conditions to pay a lot for poor access and poor/rationed care.
Regarding bad deals: That “Silver” plan the article touts has a 45 dollar co-pay for a doctor visit.