Well I think Beyonce has a point, and when she said it, Rihanna was the first to come into mind, you know, people like Katy , GaGa, and Ke$ha try to come up with a concept for their albums. Partly because they write a lot of what goes on their album so they can stick to a concept. Teenage Dream for example at least had this whole bubble-gum candy feel that went with the whole that stereo-type of a teenager.
With Rihanna, her albums all sound like four singles packed with filler album tracks, mostly her last three efforts: Loud, Talk That Talk, and Unapologetic. Especially, Talk That Talk. I think Rihanna has just sort of become molded into that, I can't blame her, its what her label wants. Hopefully though she's gained enough respect in her career to be able to have a say in what she wants. Cause you never really hear Rihanna talk about what the album is going to be like, she usually says "Yeah it'll be out soon, I just recorded some tracks #Navy".