To put a different spin on these old vinyl records, I listen to old, noisy jazz recordings because (1) that's often the only way to hear the original artists playing the music, (2) a lot of it is actual "period music", recorded when the music was fresh, new, and popular, and the musicians spoke the music properly, (3) there are some great jazz musicians that you can only hear off scratchy old vinyl, and (4) there are some excellent performances that are worth listening to, even with the noise.
I think (1) and (2) are related, and maybe not quite the dominant factor in classical music, although there's about 40 years worth of classical music recording history that might be counted as prewar, so it certainly applies to music of that period. The other reasons certainly apply to classical.
To put it closer relation to historic classical music, the Preservation Jazz Band comes to mind of an example where the musicians aren't quite old enough to have played all of the period music, but might have heard it from those who were. I'd certainly want to hear how those guys played in the fifties, even if it means listening to snap, crackle, and pop. (Okay, so maybe most of them really are that old.)