iPad Garageband files to Mac - why don't they talk to each other?

Using GB on my iPad Mini and prefer the drums to the ones in Logic. Is there anyway to export the tracks to GB or Logic on my Mac? I am not interested in it being just the audio, as I want to continue to manipulate it (change the tempo at least). Why aren't GB files on the iPad & iPhone easily transferable to the same program on a computer? Anyone know a workaround?