For more on the not-at-all-fraught issue of whether or not having health insurance improves your health, Stan Dorn and Michael McWilliams provide some extensive reviews of the literature and conclude that the overwhelming preponderance of the evidence suggests that having health insurance improves health outcomes including mortality.
That said, to be even having this conversation is for the right-wing point of view to win the argument. It’s like the fake climate change “debate”—the point is not so much to actually persuade anyone of anything but simply to shift the rhetoric around. A lot of people have perfectly good selfish reasons to want to resist comprehensive climate legislation, but few people are comfortable self-consciously espousing selfish political beliefs. So it’s comforting and useful if they’re able to instead anchor themselves to the idea of some “controversy” over whether or not uncontrolled greenhouse gas emissions are harmful. And you see something similar here. There’s obviously a lot of discomfort with the idea of a highly moralized debate about the values implicated in the decision to support or resist efforts to expand access to affordable health insurance, so creating an air of technical controversy around the fact that the exact degree to which lack of insurance is harmful helps resterilize things.