You have a point for most hip-hop/rap of the 2000's+. I'd say most great songs of today require you to dive into "the indie scene", which wasn't like that in past generations.
I suppose you guys are right. The mainstream scene is just terrible now and perhaps I have to dive deeper to find someone new that I would enjoy. I live in Austin, TX so if I do listen to radio stations I usually listen to 93.7 (classic rock) and 101.5 (classic/alternative music). Most of the new rock songs they play on 101.5 makes me want to immediately change it to 93.7. This from a rock station this is independently run and supposed to play rock even the indie scene. Austin is a pretty big center for music right now so I just assumed the rock 101X plays was the best the mainstream/indie scene had to offer. I'd have to say rock has taken just a big of a hit in quality as rap has.