HMOs require you to get a referral from your primary care doctor to see a specialist, which has the added benefit of making sure people actually have a PCP. Primary care is one of the few types of care where the more you apply it, the better a patient's health outcome.
No one gets an HMO because they're scared of having less choice of which doctors they can see. They pay more to have a choice that's ultimately irrelevant to their health. Most people choose doctors based on friend/family referrals and Yelp reviews, meaning they don't know how to choose a doctor. Reviews/referrals have no relation to health outcomes.
The end of the article refers to the "medical loss ratio" enforced by the ACA, which did indeed incentivize insurance carriers to tolerate higher healthcare bills. This affects PPOs much worse than HMOs. It should all be burnt down.
Further reading, one of the best books on the subject: "An American Sickness"