I definitely thought she was saying that the only real acceptable way to use your MD is to treat patients full time. A few quotes from the article (in addition to the one you mentioned above):
"We can no longer afford to continue training doctors who dont spend their careers in the full-time practice of medicine."
"I have great respect for stay-at-home parents, and I think its fine if journalists or chefs or lawyers choose to work part time or quit their jobs altogether. But its different for doctors. Someone needs to take care of the patients. "
Anyway, regarding the debate about part time doctors, I think that both sides have some great points. I think that prospective medical students should not pursue a career in medicine if they plan to work part time for the rest of their lives. This doesn't makes sense with regards to the costs to taxpayers, the personal monetary costs of medical school, and the time costs of training.
With that being said, I'm sure that very few medical students ever plan to work part time after receiving their degree and training. But sometimes life gets in the way. My mother's best friend (who is a OB/GYN) ended up working part time for most of her career after having a child with a mental illness that required a significant amount of extra care. I've also met and read about many female (and male!) physicians who had to work part-time for a few (or more) years because they became single parents and did not have a large support system to get through the tough time.
Anyway, I think it's much too complex to say that working part-time as a physician is always bad or always good.