Why Kylie will never be Madonna

Popjustice has a great summary, cherry-picking quotes from the web's Minogue-o-maniacs. For example: "Kylie just doesn't have the voice to make it really work" and "She's slapped us in the face again".
I have a feeling that people were expecting some kind of revelatory, heart-on-her-sleeve bombshell. After all, Kylie has had an incredibly harrowing three years - from being diagnosed with cancer, to having chemotherapy and reconstructive surgery. Not to mention splitting up with her long-term boyfriend and shelving dates on her celebrated comeback tour because she wasn't back to full health.
But then Kylie has always been strangely mute about her personal affairs. Anyone going to the Showgirl Homecoming concerts would have seen that her main priority was to dress up in feathers and bask in the fervent adulation of her fans. There were no tear-jerking moments where she revealed her innermost thoughts and passions - unless Kylie secretly wishes she were a robot from Doctor Who. Which is a possibility, I suppose.

Kylie's talent is to act as a cypher for the listener - a blank screen on which you can project your own experiences. That's why she'll never be Madonna, Janet or even Christina, all of whom use music as a spiritual and emotional enema.
Perhaps she's genuinely got nothing of interest to say, but I suspect she's too scared to relinquish control.
And, in the end, that's why her fans are upset. After supporting her through a particularly rough patch, they expected something in return - only to find Kylie had retreated further into her cocoon.
Not that anyone wants a full-on cancer album, you understand. But just a hint of the person behind the bottom would have been nice.