So how can a great system solve less than great recordings

how condescending to suggest people don’t understand this point.

Actually, it is not condescending but right. Yes its about making the music sound better. But, The music sounds best when it is brought forth in the purest of signal from the source material. This was the goal of high fidelity., to be faithful to the music as recorded. That means not adding or subtracting anything to/from it. Adding things to make it sound better, IE tone controls, is often a band aid to fix something in the signal. However, it brings about distortion. The shortest path of a signal is what is desired. Adding controls IE tone controls adds to the signal.

FWIW, I have found that as my system gets better, my music also sound better. Of course there are some which don't sound as good as others. And some are just...YUK. But the vast majority sound good overall. 
Some may hear it differently. IMO, Some are more into the sonic character of the music more than the music itself. I am into the music itself. I have no desire to hear a  great sounding recording that does nothing for my soul. IE, I don't play Female vocals and have no desire to listen to that. It doesn't move me, no matter how good the recording is done. If someone else enjoys it, then fine. I'll take the lesser recorded music