I'm always going to be a little skeptical of any study that has such a headline-grabbing thesis... More importantly, though - as you do point out - that kind of broad study is only going to have validity on the level of very broad analysis, not on the level of analysis of individual pieces of music or performers. If you think that pop as a whole is getting worse over the passage of time, to me, that's a different opinion than saying pop is intrinsically shitty. The first one is at least considering it seriously and giving it the option of being good and allows you to consider individual songs on their merits; the second one is the one that just dismisses it out of hand. Rummaging through monotony to find gems doesn't bother me; what annoys me is the idea that there couldn't possibly be any gems because 'pop music is awful'.

Again I don't really care whether you listen to pop music, I'm just saying, it's not all awful and it's not all about awful topics. That's just not true.