Hearing crap 'back in the day' and hearing it now brings you to the same conclusions. There's no mystery. We have plenty of examples from way back when too.
Agree! There was tons of crap back then as well. Always has been loads of crap, always will be. But also will there continue to be plenty of great stuff IF you know where to find it. (Clue: it likely will not be on your car's FM radio dial or played at your local Kohl's store.) IMO, it is not that today's music sucks (any more than yesterday's or tomorrow's), but more an issue of accessibility - are you looking in the right places for it?
And back then, what made it worse than today for consumers (yes, it was far worse back then), was not so much the amount of crap, but that there was no youtube, samples, internet, podcasts, self-produced releases, etc. where you could research and/or listen to weed it out from the good stuff BEFORE you plunked your $3.99 down for an album. Nor were there self-produced releases so much great music went unrecorded, or at least poorly distributed, due to record company twits who were unable to categorize the music or recognize great talent. FM radio was better back then, depending on your city, but most of the time you had to just take a chance on a musician's reputation or album cover art to try to predict whether you were buying crap or gem.