For me that was the best idea. If Medicare could do a better job, people would go there and private insurance would lose them. If Medicare sucked, people would voluntarily leave and return to private, commercial, for-profit insurance. No public expenses. Freedom of choice. Free market competition! Exactly what the Republicans said they wanted! Why did you kill it then? (As Medicare did not provide massive political sponsorship, the public option was cheaper!)
I am not sure that the proposal "Medicare for All" is really just a reinstatement of the option "Pubic" or a mandatory transfer of all to Medicare. It could be either one.
Do you know Medicare has a much higher customer satisfaction rating than commercial insurance?