What does white have to do anything? There were plenty women of color around the time she started and after. Whitney gets credit, Janet gets credit, Diana Ross gets credit, Donna Summer gets credit. Not a race issue.
She's reinvented her image and sound practically almost every album campaign in regards to sound, style and image. It wasn't a late 2000's thing.
She began selling less after her departure from Warners and focused more on touring when she signed a deal in 2007. Since then, it's been primarily focusing on touring where she considered the profit would be made and less on her records. Hard Candy got some promotion, MDNA got virtually nothing outside of the Superbowl and the tour itself and Rebel Heart she seemed more interested in her work.
Desperate to stay controversial and current? She's been that way since day one going against the norm and pissing people off. Her rebellious attitude towards how women should behave, act, dress, what they can and cannot do is pretty much the blueprint a lot of female artists now follow and she set the template for them. Artists always feel they need to create and it's those that keep going that show passion towards their craft. She could bank on her hits but chooses not to and whether her newer material is good or not is up to the listener.
She's had the music and several other things to back it up, not just changing her style.