I tend to refrain from one-sentenced opinions when it comes to things as vast as a whole decade. I don't think it's fair to say that "the 70's were worse than the 60's" or "the 80's suck" or anything like this, because we're not talking about a song, or an album, but a whole freakin' decade. Yes, some of the 70's and 80's mainstream may have sucked more than before (Eagles selling that many albums is a crime). But let's not forget that there's much more to it than the radio hits. Tons of different musical scenes, filled with tons of different artists, playing tons of different styles. It has always been that way and it still is now. I don't see how it can be possible for one to hate a decade as a whole (hell, even a year as a whole), unless the said person hates rock/jazz/pop/blues/etc. music altogether. It's just way too vast of a subject, and deserves days and filled forum pages of analysis.
This is not a replay to anybody in particular, just some thoughts.