I don't think it gets quite mentioned explicitly in this video, and don't I know if it's what the parent comment was referring to, but I recently learned the interesting detail that this lock system was invented for the international NES, and was not a feature of the original japanese Famicom. And apparently Nintendo did have a bit of a problem with large numbers of bad unlicensed games in that market.

This apparently was a small motivator in the development in the japan-only Famicom Disk System, a floppy-disc-like drive addon, which did use a protection system that amusingly was based around trademark law. There was a number of other interesting elements about the Disk System, but I'll suppress my desire to vg history ramble :)