Problem here is the persons in question have screens with allegedly 'poor' black levels themselves. Nobody likes to see their own kit denigrated, or weak points 'pointed out' (not the same screen, but same weak points) As you say, what the issue is, is that the photo shows up the poor black level, but they rightly say that in the real world it matters less than you might think. Your brain 'reprograms' itself to accept as black, a level of grey which is the darkest the screen can produce. Side by side the difference is like chalk and cheese, but on the wall in your house, why get hung up on it. The fact that the camera never lies is beside the point.