Premier Rush export filesize ridiculously large

Has Adobe fixed this problem yet? 

I upload an mp4 video file that's 16 MB. I don't touch or edit it at all, and go to export it at 720p. The filesize is 71 MB. Why?? But get this: Then I try adding two random cuts to the video clip. I go back to export the file. It is now 1029 MB!!! What the heck is wrong with this application??