"Firework to me is a movement. You can always sing songs about bitches and hoes but I think it takes a little bit more to do a song like 'Firework'."
Can I remind you that Katy wrote Firework with not one, not two, not three, but FOUR other people? Not to mention the fact that the other writers are all prominent songwriters, meaning that it is likely that Katy Perry actually contributed even less than her expected load of 20% of the writing. She didn't do anything to contribute to the song other than the minimal writing and her largely autotuned vocals, which is apparent from the lack of a single decent live performance of Firework (aside from Jessie J at the VMA's). Katy didn't "do" this song. She had it handed to her on a silver platter.
But what truly amazes me the most is that it took five people to come up with a line like "Do you ever feel like a plastic bag?"