Even if that is legal (it isn't)

1. Are you a lawyer?

2. I am not a lawyer, but I have talked to lawyers about this before and their answer was basically:

The owner of a copy of a game or other computer software may "make or authorize the making of another copy." Legally speaking, the law does not require the person who owns the copy to personally make the backup copy, nor does it specify that the backup copy be made only from the copy owned.

This is important because on Nintendo's own website they state the following:

Therefore, whether you have an authentic game or not [...] it is illegal to download [...] a Nintendo ROM from the Internet.

What Nintendo is saying here is outright wrong. A person who only has only temporary possession of a game (such as rental or borrowing) gains no rights under 17 USC 117, and may not download a copy without separate permission, which obviously Nintendo would never grant However, A person with permanent possession of a game (such as a legally purchased game either from retail or used) DOES gain those rights to an archival copy. These rights supercede any restriction on those rights Nintendo would presume to apply. Nintendo presumes to add extra conditions and terms that do not actually exist in the law.

The purpose of the archival copy provision is to protect legal owner's access to the computer software in case of damage. If your copy of a game breaks, such as a broken CD, you have the legal right, as owner of that CD, to continue to use the computer software on that CD no matter its physical condition. An archival copy could then be used to create a working version of that CD so that you, the legal owner of that copy, may continue to access that computer software. This is also the case when access to that software becomes difficult or impossible, such as a game or other computer software that is stored on archaic storage media such as a floppy disk or paper tape.