So how can a great system solve less than great recordings

You're over-generalizing. At this level of analysis anyone can say Edison made lousy recordings on his wire thingy, the gramophone sucks, how can even the best system get fidelity from tin cans and string? Fraid you're gonna have to up your game a little to have something more to talk about.

You pay your money. You take your chances! Considering the problems of capturing sounds with a mike it is a wonder that there are so many good - and better - sounding recordings available!

If you’re interested in classical and jazz then you should see the remastered reissues from Pristine Classical. They take albums from the 20s to the 60s and make them absolutely amazing with their XR filtering.  You can’t almost tell the difference between a a recording on the 30s and 60s. 
Their recent Miles Davis reissues are sublime. 
You can also stream from their website. 

The original question is based on a profound and yet all too common misperception about high end audio. It is not about making recordings sound good. The very best cost no object system cannot possibly ever make anything sound good. That is a completely inside out and backwards understanding. What the very best components and systems do is nothing. Nothing. Not one tiny little thing.

Well, except amplify so we can hear. But other than that, nothing. The whole point is to be able to hear the original recording in as much fidelity as possible. Fidelity by the way means truth. High fidelity means highly truthful. Does not mean good. Truth ain’t always pleasant to hear now, is it?

Case in point.

Hi end (and the rest) systems remain at the mercy of lesser quality recordings, past and present.

tried a rolling stones album and it sadly didnt sound so good, ‘ let it bleed’.

its sad. Thats all.

Fortunately, linda ronstadt albums sound really good.  Some stuff from that era were done better.