Well, I think some of it is just nostalgia for the old days. After all, what high devotion to musical art produced Ella's smash hit a tisket a tasket? And, she followed it up with a rendition of Muffin Man, hoping to repeat the success. Luckily, that one never caught on.
I've heard just as many untalented old codgers as I've heard untalented young people. Well, maybe not quite as many, because not everybody had access to instruments to the degree we do now. But still, I've heard enough scratchy fiddles and 3 chord wonder guitarists from my grandpa's era to know that not everybody back then was a Stuff Smith or Charlie Christian.