You don't have to choose between universal access and innovation. It's possible to have both--as long as you do it right.
By universal access, he means a government-run system. By innovation, he means wonderful new medical procedures. The article discusses the fear that if government cracks down on spending, then innovation will slow down. He says that this is a reasonable argument against a government-run system, but not if you "do it right."
The Masonomics perspective is that there is no known way of doing things right. It is not just medical treatments that require innovation. The entire health care system and all of its institutions could benefit from innovation.
The advantage of markets is that they foster innovation. They reward successful innovation. Moreover, they eliminate obsolete institutions and organizations.
Government is much more likely to protect incumbents. Regardless of whether it stifles innovative treatments, government will certainly stifle innovative ways to organize and deliver health care. Indeed, it already does so, with its restrictions on medical licensing and practice. A complete government takeover could only make things worse.
From that perspective, Ramesh Ponnuru is correct to point out that the real radicals in health care reform are not to be found on the Left. Even a single-payer system, which none of the leading Democratic contenders openly endorses, is not much different from what we have today. It is those of us who are willing to pull the government rug out from under the existing system who are the radicals.