EDIT:
Also, I don't want to get into the specifics of how effects and video editing are done, but copying a project and it's materials is not the same as copying downloaded movies. Things have to be relinked to new file paths, re-rendered, fixed etc. Lots of pro-apps and plugins have to be installed/tested. It takes time, especially if you have a lot of developed stuff. Getting everything seaworthy and ready to go could take at least a week, so I don't wanna have to do that 2 times in a row and loose an extra week.
Not to mention those annoying node-locked licenses where you have to get the company to provide a new serial number or allow for another activation.