I like her, too. And my musical preferences are contemporary classical, experimental electronica, indie rock, world music, jazz, even free jazz of better sort, but I noticed her.
I once saw "Fireworks" on TV and thought - this is superficial and stupid only on the surface - but looking at it differently - this is really great modern pop - the girl can sing, has some special appeal in the voice and appearance (quasi naive, but underneath sexy and innocent beauty, but raw and wild at the same time), the music sounds robotic at a first listen, but it is quite groovy, and actually partly played - real instruments among all that synth stuff, clever arrangement, outstanding vocal production - so much attention towards details - of course this is not to be compared to some great classical, indian or persian classical or soul singers, but in a field of its own - it is a very good vocal achievement - it communicates with audience, it doesn't stay on the surface AND the songs have some MOJO - she has that "something".
I could never grew really fond of a more crazy Lady Gaga or either a very sexy Rihanna or a pioneer of that kind of girly pop - Britney Spears - they just don't seem to have that kind of voice and some sort of intelligence that Katy Perry has. (ok, Lady Gaga is cool and intelligent, but doesn't have that "something" that appeals to me in Katy - and no, it's not the looks).
If she would be really smart she would invite those "Dirty Loops
" guys to be her live band and also made a funky acid-jazz-pop record with them. Sharing the mic with their singer... That could be really great.
So, yeah, despite otherwise having a completely opposite music preference, I listen to her music on a mp3 player while jogging. It is uplifting, groovy, intelligent (in a tongue in cheek kind of way - "Peacock", etc. ) enough not to insult me.
edit: just saw that live video - yes, she has some special charisma
and I think I like the colour of her voice and if it's true that the soul reflects in your voice - she must have a nice soul - there is something I like in that voice, although there are thousands of technically better singers.