Answer: If I understand your question right (it looks like you're an American) you want to know why some Americans say that some British say the NHS is no good? I'm only guessing here, but is this because you want to know if this is good evidence that the NHS is actually no good?
I plan to write a whole piece about the NHS vs. what America has or doesn't have. I've made good use of both health systems. I had great health insurance in the US. There are things about the NHS that I don't love, but it has done a lot for me. I was sitting in a doctor's office just a couple of weeks ago. I told her what I'd found out about the affordable care act, something I've pinned my hopes on for being able to get health insurance as a self-employed writer. With my boyfriend who will soon be my husband, we'd spend $10,000 a year for health care on the best health insurance plan I could find under the affordable care act. We spend less than $1000 a year here.
So anyhow, I was talking to this doctor about the fact that I didn't think we'd be able to move back to the US because of the cost of health care. She said, "People complain about the NHS but they don't know how good they've got it." I think that's the thing. There really is always something you can complain about. Waiting times can be long. The British government is doing its best to gut the NHS and replace it with American style health care coverage. But the truth is the great majority of Britons can't afford anything like what the Americans have. People will complain, but they don't have anything to compare it to. I complained about various things when I was in the US and I had amazing insurance that covered nearly everything.
The NHS could be better in some respects, but it is already better than much of the health coverage that many Americans have. And Americans mistakenly think that it's the only coverage available here. There is also private insurance. Some people use both. I'll write a whole piece on this when i get a moment.
But my verdict is that the NHS is actually close to miraculous, and definitely worth fighting for.