I personally think the main reason the Born This Way/Express Yourself issue kicked off was due to Gagas fans. There's so many of them online who try to imply that Gaga is one of the most original pop stars of all time and that everyone these days are inspired by her/ripping her off that as soon as there became an opportunity to state the opposite everyone jumped on the bandwagon and it snowballed from there.
Katy doesn't have the same 'She created the heavens, the earth and the music' stigma, so no one cares that her song sounds like someone else's.
