I agree that it's a company wide policy, but I'm not so sure it's to reduce load. It might just be that they want more subscription revenue and to reduce their reliance on advertising, which has current antitrust issues circling around it.

My point is that there is no "file" for Google Docs. They are some rows in a database somewhere. Probably some update rows and the occasional snapshot proto.

I guess it is no less arbitrary than a MS Office file, but since you can see the file on your disk you know the intrinsic size.

I'm definitely not saying they should give away the storage for free. But it is an interesting problem for how to count this in a user-understandable way.