Some artists aren't able to start their career singing songs that they write. Carrie Underwood who came up from American Idol is one of those artists. When you win a reality show you're pretty much at their mercy for the first few singles until you prove yourself as a viable artist.
Obviously Carrie did that with super hit single after single, so when it was time to show off her writing skills she was a bit fearful of not being taken seriously. It's #TBT so take a look and listen at the first single Carrie wrote for herself "Mama's