ATRL sistrens like to diminish M's impact. Is it because she's out sold and out-grossed everyone's faves? Is it because she gave most modern pop girls a career?
Because she is and always will be the queen of pop. She's untouchable and has reached a status no other female pop singer will ever reach. So jealousy is the answer, I suppose.
It's very, very easy to diminish and undermine her accomplishments (and therefore make someone else's accomplishments look better in comparison). Just ignore her natural creativity and talent, claim she owes all her success to her whiteness, her exploitation of her own sexiness, and her business mentality. And there you have it: a pressed ATRLer.