Don't blame her, or Bizet. This is a transcription, so blame the transcribe.That said, octaves would make it harder. With these "easier piano" type transcriptions you should feel free to embellish as your abilities and tastes dictate.You probably should have the same freedom with the really show-offy very advanced ones, too, but they're generally challenging enough without trying to add extra bits.
I don't think that lady could handle octaves.There's got to be a better solo transcription of that.... Hmm....