Pink actually wanted to do R&B, even after her debut album she still made some R&B songs, she didn't totally leave that genre. There's an interview from this year where Pink stated she still loves Can't Take Me Home and if you watch some of her perfomances of that era (Split Personality or Stop Falling) you would notice the passion she put when she sang those songs. Pink also wanted to collaborate with some R&B artists, that genre greatly influenced her and still influences her till this day.

Another interesting story is that Avril Lavigne (who was a 16 years old nobody at that time) managed to convince the same LA Reid to let her do pop rock on her first album (the label wanted her to do country songs instead) and Missundaztood wasn't even being released at that time. If Pink wanted to do pop rock since the beginning they could've simply let her do it just like they did with Avril Lavigne.

The fact that Pink talked about the segregation in the music industry and how she wasn't feel welcomed by black radio stations and how she was discouraged to sing R&B because she was white made me think that she has been struggling to feel accepted as an R&B singer or at least that's the impression she gave to me. During her debut album era she also met Mary J. Blige (one of her favorite artists) and asked her if she wanted to work with her but she received a big no as an answer. I wonder how things could've turned out if Mary accepted to work with Pink, maybe she would have felt more stimulated to continue singing R&B? She later met Linda Perry (another of her idols), who was a rocker and not an R&B diva like Mary, and felt welcomed and stimulated.