And last year Beyonce, given a similar lengthy slot, moved through a spectacular presentation that ran the entirety of her groundbreaking self-titled visual album.
VMAs need Gaga for her technically perfect, ground-breaking performances, Katy for ha tween fans to draw numbers, Kesha's comeback to slay haters, and Madonna to perform "Bitch I'm Madonna" and drag ageists for FILTH.
All the weight was on Taylor, she was the only A-list female there Nicki and Miley are too and they're a big mess so....
Bey pretty much carried the entire show last year as the only confirmed A-list performer and I think that's been MTV's primary issue lately -- not being able to book multiple A-list names for confirmed appearances/performances ahead of time. When they can get multiple major names in like 2011/2013, the ratings spike.