This is one of those subjects where there could never be a real answer because people will always think their generation is great and the current one is shit. In 10 years, you youngins will complain about the music of that time and think now was great.
It's a vicious cycle.
Just to note, this doesn't go for everyone, as I love 70's and 80's music and think it is the best music ever made <3
Being a teen in the 90's, the music wasn't that bad, really, I just still prefer 70's and 80's.
Now, music is just horrific. Not as many artists sing songs with feeling because the songs are written by someone else so you don't feel the 'realness' of it, there is no connection, and a lot of technology is used to make the music sound the way it was. Back then, you had a bunch of dudes/chicks on stage playing with instruments and singing for real.
Even the image has changed. Back then, you could get a fat dude like Meatloaf to be a big star but now, wow, good luck thinking a random fat dude could be on Britney's level of fame. Not saying all artists/bands are made of hotness but a person/people who don't fit a certain mold wont ever be as popular as someone who is made to be 'perfect'.