Most people I know think modern music is bad but older music is good.
My general opinion is this, mainstream music from previous generations were good but after the invention of the internet people branched out to many other genres of music not recognized in the mainstream, by all definitions of good music these genres cover, they have melody and complexity but most people see this generation by what they hear on the radio, very simple, very repetitious, but not always bad, I mean very few actual music critics would attack artist like Radiohead, Jay-Z and a couple other mainstream artists. Other people refuse to recognize this though. The top 20 is dictated by MTV, Disney and other organizations and with very few exceptions good music is replaced with whats marketable. This doesn't mean good music is dead, like my point earlier I would say the majority would be about 30% of the actual market, the 30% though is the largest percentile, we have the "Old music is better" like you that makes a good portion and a large group that would be labeled other. This other group was created by the internet, an Idea that good music is stuff that is out there stuff that is original, they are the Jazz, Rock, Metal and Punk of this generation, with genres that are new and sound different then anything that has ever been done before. My never ending love for Post Rock for example, not very many people have heard of it, but bands like Godspeed you! Black Emperor and Sigur Ros are now being recognized by mainstream publications, simply because there is a big enough minority that listens to it. Yet people wont look pass this generations big flops like Justin Bieber or Hannah Montana, and its a shame really.
Also to the second part,Brian Eno, Radiohead, Sonic Youth, Sigur Ros, Vampire Weekend, Forseti, OOIOO, Sleater Kinney, The Strokes, Interpol and Joy Division.