I'd draw a different conclusion. For starters, keep in mind that public sentiment on this question hasn't changed much over the past decade. There are some ups and downs in recent years about the quality of national health care coverage, possibly based on the ups and downs of Obamacare, but it mostly looks like noise to me.
More importantly, though, I don't interpret this as a belief that coverage for other people is either bad or wasteful. I interpret it as a surprisingly accurate assessment of U.S. health care. About two-thirds of Americans have either Medicare or company-provided health care (or something similar), and they correctly tell Gallup that their own personal coverage is pretty good. And it is! At the same time, most people also think that overall health care coverage in America is pretty mediocre, and that's true too. How can you call national coverage good or excellent when 50 million people are uninsured and have crappy access to medical care?
If Gallup had called me, this is precisely the response I would have given them. My own personal coverage is quite good. Thanks, MoJo! However, I'd also say that overall coverage in the U.S. is terrible. Obamacare will, perhaps, upgrade that to merely unsatisfactory, but that's about it.