Because she was so cute and fun.
Also, almost everyone in EG had their silly high school dramas going on (Even Sonata's band mates had this "mean girls" thing going.)
while Sonata is like, "Tacos!"
Like I said, she seems like a lot of fun to be around, and is above the annoying drama. That's why I like her.
I actually have a conspiracy theory about Sonata actually being the smart one in EQ for the reasons just stated