One of the most important provisions of the ACA was the caps on the "medical loss ratio", the percent of insurance premiums paid out for medical care. The act required insurance plans to maintain a MLR no lower than (IIRC) 70-80%. Before then, plans (eg, targeting college kids) had MLRs as low as 10%.

(For comparison, Medicare/Medicaid has something like a 95% MLR, because it has low administrative overhead and isn't returning a profit to shareholders.)

17x upcharges, if they were extracted at the insurance level instead of the hospital level, would be the equivalent of a MLR of around 6%.

This of course has the unfortunate side affect of rewarding insurance companies for overpaying for medical care by allowing them to raise premiums and thus generate a higher profit.