My theory is that it's because children have too much power because adolescents don't buy music at all, and labels invest too much in tween acts as a result.
All these new acts, Lorde, Meghan, 1D, 5SOS, Ariana, etc. are all aimed at tweens, and that's why the current pop scene is so terrible
Early 00's had J.Lo, Shakira, X, Beyst, Non-sucking P!nk as strong fierce non-teen women selling like crazy. I miss those times
Now we are stuck with the likes of Ariana, I love my sis but she is so so soooooooo basic