Also there is many pop music that gets good ratings from music critics, so to say "it's crap nowadays" just isn't true, and from hearing CHR music from almost every decade...there's plenty of "crap."
If you use similar criteria as do your critics and you both agree a certain song, decade, genre, era is not junk then so be it. For reasons I illustrated in another post I put no credence in critics. I will consider other opinions but I do not depend upon them.
I will agree that every era has its poor music when compared with the general music population. However, my point was directed at comparing entire eras and enough of my peers (as well as younger people who seemingly have no axe to grind) seem to agree that popular music in general today isn't near the quality of that past, however you define it. Most of the groups you mentioned were, BTW, more current than that I was discussing. "Bohemian Rhapsody" will be perhaps the single song from that assortment to have longevity years from now and even that could be considered a light novelty song.