It's how EVERY DRIVE in the history of computers work!
If I take my files out of my HD, they will be deleted from the HD. If I move my files out of my flash drive, they will be deleted from my flash drive.
The only way that I would be surprised by this behaviour is if I had never used a computer at all in my life.
No. No, it's not. I have experience with Google Drive, iDrive, SkyDrive and DropBox. The only oddball one that leads to losing data like this is Google Drive.
With SkyDrive, it works very similar to DropBox. Your cloud drive is just a folder on your disk, synched between multiple computers. If you move a file from your cloud drive to your local drive, it moves the actual file - not a pointer to it.
Google Drive is a terrible morass of confusing design. It's not an exaggeration to say they should shut down and start over.
document.gdoc is not a file, you are mistaken